Target Mathematics

Past-paper practice

Trigonometry: Topic Questions

103 questions with mark schemes.

1.1: Areas using trigonometry

4PM1/1/November/2025 — Question 3 · 6 marks

1.1 diagram 1
Figure 1 shows triangle ABCABC where
AB=12cmBC=15cmAC=xcmBAC=60AB = 12 \mathrm{cm} \quad BC = 15 \mathrm{cm} \quad AC = x \mathrm{cm} \quad \angle BAC = 60^\circ
(a) Show that xx satisfies the equation
x212x81=0x^2 - 12x - 81 = 0
(3)
(b) Hence find the exact area, in cm2\mathrm{cm}^2, of triangle ABCABC
Give your answer in the form 9(pq+r)9(p\sqrt{q} + \sqrt{r}) where p,qp, q and rr are integers.
(3)

1.2: Trigonometric identities and equations

4PM1/1/November/2025 — Question 11 · 10 marks

(a) Using a formula on page 2, show that
1cos2A1+cos2A=tan2A\frac{1 - \mathrm{cos} 2A}{1 + \mathrm{cos} 2A} = \mathrm{tan}^2 A
(3)
(b) Hence, or otherwise, solve in degrees to one decimal place
33cos4x1+cos4x+5sin2xcos2x=2for90<x<90\frac{3 - 3 \mathrm{cos} 4x}{1 + \mathrm{cos} 4x} + \frac{5 \mathrm{sin} 2x}{\mathrm{cos} 2x} = 2 \quad \mathrm{for} -90^\circ < x < 90^\circ
(7)

1.5: Intersection of two circles

4PM1/1/June/2025 — Question 3 · 6 marks

1.5 diagram 1
Figure 1 shows circle C1C_1 with radius 7 cm and circle C2C_2 with centre OO and radius 7 cm
The circles C1C_1 and C2C_2 intersect at the point AA and at the point BB
The size of angle AOBAOB is θ\theta radians
The perimeter of the region RR shown shaded in Figure 1 is 28π9\frac{28\pi}{9} cm
(a) Find the exact value of θ\theta
(2)
(b) Find the area, in cm2\mathrm{cm}^2 to 3 significant figures, of the region RR
(4)

1.6: 3D angles in a pyramid

4PM1/1/June/2025 — Question 8 · 13 marks

1.6 diagram 1
Figure 3 shows a right pyramid with vertex VV and square base, ABCDABCD, of side 12 cm
The size of the angle between the plane VABVAB and the base ABCDABCD is 3030^\circ
(a) Show that the height of the pyramid is 232\sqrt{3} cm
(2)
(b) Find, in cm, the exact length of VAVA
(3)
(c) Find, in cm2\mathrm{cm}^2, the exact area of triangle VADVAD
(3)
(d) Find, in cm, the exact length of the perpendicular from DD to VAVA
(2)
(e) Find, in degrees to one decimal place, the size of the obtuse angle between the plane VABVAB and the plane VADVAD
(3)

1.7: Trigonometric equations and geometry

4PM1/1R/June/2025 — Question 4 · 7 marks

Triangle ABCABC is such that
AB=4.3cmAB = 4.3 \mathrm{cm}
BC=5.9cmBC = 5.9 \mathrm{cm}
angleBCA=29\mathrm{angle} BCA = 29^\circ
(a) Find in degrees, to one decimal place, the two possible values for angle CABCAB
(4)
(b) Hence, find in cm, to 3 significant figures, the shortest possible length of ACAC
(3)

1.8: Trigonometric identities

4PM1/1R/June/2025 — Question 10 · 15 marks

1.8 diagram 1
(a) Using a formula from page 2, show that
(i)sin2A=1cos2A2(i) \mathrm{sin}^2 A = \frac{1 - \mathrm{cos} 2A}{2}
(ii)cos2A=cos2A+12(ii) \mathrm{cos}^2 A = \frac{\mathrm{cos} 2A + 1}{2}
(5)
Figure 2 shows part of the curve CC with equation y=sinxy = \mathrm{sin} x and part of the curve DD with equation y=cos2xy = \mathrm{cos} 2x
Curve CC and curve DD intersect at the point AA
(b) Use algebra to find the exact coordinates of AA
(5)
The shaded region RR is rotated through 360360^\circ about the xx-axis.
(c) Use algebraic integration to find the exact volume of the solid generated.
Give your answer in the form aabπ\frac{a\sqrt{a}}{b}\pi
where aa is a prime number and bb is an integer.
(5)

1.4: 3D angles in a pyramid

4PM1/2/November/2025 — Question 11 · 11 marks

1.4 diagram 1
Figure 4 shows a right pyramid ABCDEABCDE with
• vertex EE
• horizontal square base ABCDABCD of side 6cm
EA=EB=EC=ED=12EA = EB = EC = ED = 12 cm
• vertical height of hh cm
(a) Show that h=314h = 3\sqrt{14}
(3)
(b) Find, in degrees to one decimal place, the size of the angle between EBEB and the plane ABCDABCD
(2)
The midpoint of AEAE is PP and the midpoint of BEBE is QQ
(c) Find, to the nearest degree, the size of the obtuse angle between the plane EPQEPQ and the plane PQCDPQCD
(6)

1.10: Areas using trigonometry

4PM1/2/June/2025 — Question 5 · 8 marks

In triangle ABCABC, AC=12AC = 12 cm, BC=14BC = 14 cm, AB=xAB = x cm and angle ABC=30ABC = 30^\circ
(a) Show that x=P3±95x = P\sqrt{3} \pm \sqrt{95} where PP is a prime number.
(5)
(b) Hence or otherwise, find in cm2\mathrm{cm}^2, the difference between the two possible areas of triangle ABCABC
Give your answer in the form mnm\sqrt{n} where mm is a prime number and nn is an integer.
(3)

1.11: Trigonometric identities, trigonometric equations and exact trigonometric values

4PM1/2/June/2025 — Question 11 · 15 marks

(a) Show that cos4θsin4θ=cos2θ\mathrm{cos}^4 \theta - \mathrm{sin}^4 \theta = \mathrm{cos} 2\theta
(4)
(b) Hence, or otherwise, solve the equation
8cos2(2θ+π4)3=2cos4(θ+π8)2sin4(θ+π8)for0θ<π8 \mathrm{cos}^2 \left( 2\theta + \frac{\pi}{4} \right) - 3 = 2 \mathrm{cos}^4 \left( \theta + \frac{\pi}{8} \right) - 2 \mathrm{sin}^4 \left( \theta + \frac{\pi}{8} \right) \quad \mathrm{for} 0 \leq \theta < \pi
Give your solutions to 2 decimal places.
(7)
(c) Using calculus, find the exact value of π16π8(cos42xsin42x8sin4x)dx\int_{\frac{\pi}{16}}^{\frac{\pi}{8}} (\mathrm{cos}^4 2x - \mathrm{sin}^4 2x - 8 \mathrm{sin} 4x) \mathrm{d}x
Give your answer in the form ab2a - b\sqrt{2} where aa and bb are rational numbers.
(4)

1.12: Circular measure and sectors and areas using trigonometry

4PM1/2R/June/2025 — Question 3 · 6 marks

1.12 diagram 1
Figure 1 shows sector OABCOABC of a circle with centre OO and radius 6 cm
The size of angle AOCAOC is θ\theta radians.
The perimeter of sector OABCOABC is (12+π)(12 + \pi) cm
The region shown shaded in Figure 1 is bounded by the arc ABCABC and the line ACAC
The area of this region is Scm2S \mathrm{cm}^2
Find the exact value of SS
(6)

1.14: Trigonometric equations and geometry

4PM1/1/November/2024 — Question 3 · 5 marks

Triangle ABCABC is such that
AC=10cmAC = 10 \mathrm{cm}
BC=7cmBC = 7 \mathrm{cm}
angleCAB=25\mathrm{angle} CAB = 25^\circ
Given that angle ABCABC is obtuse,
find, in cm to one decimal place, the length of ABAB
(5)

1.15: 3D angles in a prism

4PM1/1/November/2024 — Question 4 · 6 marks

1.15 diagram 1
Figure 1 shows a right prism ABCDEFABCDEF
Triangle CDECDE is a cross section of the prism.
DCE=ABF=90\angle DCE = \angle ABF = 90^\circ
EDC=FAB=40\angle EDC = \angle FAB = 40^\circ
DE=AF=15DE = AF = 15 cm
EF=DA=CB=20EF = DA = CB = 20 cm
Find, in degrees to one decimal place, the size of the angle between the line FDFD and the plane DCBADCBA
(6)

1.16: Trigonometric identities, trigonometric equations and exact trigonometric values

4PM1/1/November/2024 — Question 8 · 11 marks

(i) (a) Using a formula given on page 2, show that
tan2A=2tanA1tan2A\mathrm{tan} 2A = \frac{2 \mathrm{tan} A}{1 - \mathrm{tan}^2 A}
(2)
(b) Hence, solve the equation
tanAtan2A=0for0A180\mathrm{tan} A^\circ - \mathrm{tan} 2A^\circ = 0 \quad \mathrm{for} 0 \leq A \leq 180
(5)
(ii) Using a formula given on page 2, solve, giving your solutions as exact values
cos(xπ6)=sinxforπx2π\mathrm{cos}\left(x - \frac{\pi}{6}\right) = \mathrm{sin} x \quad \mathrm{for} -\pi \leq x \leq 2\pi
(4)

1.19: Areas using trigonometry

4PM1/1R/June/2024 — Question 3 · 8 marks

1.19 diagram 1
Figure 1 shows triangle ABCABC where
AB=xcmAC=(x+7)cmBAC=30AB = x \mathrm{cm} \quad AC = (x + 7) \mathrm{cm} \quad \angle BAC = 30^\circ
The area of triangle ABC=36cm2ABC = 36 \mathrm{cm}^2
(a) Show that x=9x = 9
(3)
(b) Find, in cm to 3 significant figures, the length of BCBC
(2)
(c) Find, in degrees to one decimal place, the size of
(i) ABC\angle ABC
(ii) ACB\angle ACB
(3)

1.20: Possible values for a sector radius

4PM1/1R/June/2024 — Question 4 · 9 marks

1.20 diagram 1
Figure 2 shows the sector OPQOPQ of a circle with centre OO and radius rr cm.
OP=OQ=rcmarcPQ=(21r)cmPOQ=θradiansOP = OQ = r \mathrm{cm} \quad \mathrm{arc} PQ = (21 - r) \mathrm{cm} \quad \angle POQ = \theta \mathrm{radians}
The area of the sector is Acm2A \mathrm{cm}^2
(a) Show that A=r2(21r)A = \frac{r}{2}(21 - r)
(3)
The area of the sector must be greater than or equal to 27cm227 \mathrm{cm}^2
(b) Find the set of possible values of rr
(4)
(c) Hence write down the set of possible values of θ\theta
(2)

1.17: Sector arc length and angle

4PM1/2/November/2024 — Question 1 · 5 marks

1.17 diagram 1
Figure 1 shows sector ROSROS of a circle with centre OO and radius 2 cm
The size of angle ROSROS is θ\theta radians.
The area of sector ROSROS is π2cm2\frac{\pi}{2} \mathrm{cm}^2
(a) Find the exact value of θ\theta
(2)
The perimeter of sector ROSROS is PcmP \mathrm{cm}
(b) Find the exact value of PP
(3)

1.21: Sector arc length and angle

4PM1/2/June/2024 — Question 3 · 6 marks

1.21 diagram 1
Figure 1 shows the sector AOBAOB of a circle with centre OO and radius 3r3r cm
A circle with radius rr cm touches OAOA and OBOB and the arc ABAB
Angle AOBAOB is θ\theta radians, where 0<θ<π20 < \theta < \frac{\pi}{2}
(a) Find the exact value of θ\theta
(2)
The area of the region shown shaded in Figure 1 is 8π8\picm2\mathrm{cm}^{2}
(b) Find the value of rr
(4)

1.22: 3D angles in a prism

4PM1/2/June/2024 — Question 9 · 15 marks

1.22 diagram 1
Figure 5 shows a right triangular prism ABCDEFABCDEF where ABCDABCD is a rectangle.
AF=DEBF=CEAD=FE=BCAB=DC=24cmAF = DE \quad BF = CE \quad AD = FE = BC \quad AB = DC = 24 \mathrm{cm}
ABF=DCE=45BAF=CDE=60\angle ABF = \angle DCE = 45^\circ \quad \angle BAF = \angle CDE = 60^\circ
Using a formula from page 2,
(a) show that sinAFB=2+64(a) \text{ show that } \mathrm{sin} AFB = \frac{\sqrt{2} + \sqrt{6}}{4}
(3)
Without using a calculator,
(b) show that BF=12(326)cm(b) \text{ show that } BF = 12(3\sqrt{2} - \sqrt{6}) \mathrm{cm}
(5)
The angle between the plane AEBAEB and the plane ABCDABCD is 6565^\circ
(c) Find, in cm to 2 significant figures, the length of EF(c) \text{ Find, in cm to 2 significant figures, the length of } EF
(3)
(d) Find, in degrees to one decimal place, the size of the angle between the line CF and the plane ABCD(d) \text{ Find, in degrees to one decimal place, the size of the angle between the line } CF \text{ and the plane } ABCD
(4)

1.23: Trigonometric identities, trigonometric equations and exact trigonometric values

4PM1/2/June/2024 — Question 11 · 16 marks

Using formulae from page 2, show that
(a)(i)cos2A=2cos2A1(a) (i) \mathrm{cos} 2A = 2\mathrm{cos}^2 A - 1
(3)
(ii)sin2A=2sinAcosA(ii) \mathrm{sin} 2A = 2\mathrm{sin} A \mathrm{cos} A
(1)
(b) Show that cos3A=cos3A+3cosA4(b) \text{ Show that } \mathrm{cos}^3 A = \frac{\mathrm{cos} 3A + 3\mathrm{cos} A}{4}
(4)
Hence, or otherwise,
(c) solve, giving exact values in terms of π\pi
8cos3(θ2)6cos(θ2)1=0for0θ2π8\mathrm{cos}^3\left(\frac{\theta}{2}\right) - 6\mathrm{cos}\left(\frac{\theta}{2}\right) - 1 = 0 \quad \mathrm{for} 0 \leq \theta \leq 2\pi
(4)
(d) use algebraic integration to find the exact value of
0π/6(4cos3θsin2θ)dθ\int_0^{\pi/6} (4\mathrm{cos}^3 \theta - \mathrm{sin} 2\theta) \, \mathrm{d}\theta
(4)

1.24: 3D angles in a pyramid

4PM1/2R/June/2024 — Question 10 · 13 marks

1.24 diagram 1
Figure 4 shows a right pyramid ABCDVABCDV
The base of the pyramid is a rectangle where,
AB=DC=2xcmAD=BC=xcmAB = DC = 2x \mathrm{cm} \quad AD = BC = x \mathrm{cm}
The edges VAVA, VBVB, VCVC and VDVD are all of equal length.
The angle between VAVA and ABCDABCD is 4545^\circ
(a) Show that VA=102xVA = \frac{\sqrt{10}}{2}x cm
(3)
(b) Find in cm, the exact height of the pyramid in terms of xx
(2)
Find, in degrees to one decimal place,
(c) the size of angle VBAVBA
(2)
(d) the size of the obtuse angle between the plane AVCAVC and the plane BVDBVD
(4)
Given that the volume of the pyramid is 959\sqrt{5}cm3\mathrm{cm}^{3}
(e) find the value of xx
(2)

1.25: Trigonometric identities

4PM1/2R/June/2024 — Question 11 · 12 marks

(a) Using a formula on page 2 show that cos2A=2cos2A1\cos 2A = 2\cos^2 A - 1
(2)
(b) Hence show that (2cos2A1)2=cos4A+12(2\cos^2 A - 1)^2 = \frac{\cos 4A + 1}{2}
(3)
The curve with equation y=sin2x2+(2cos2x1)22+18y = \frac{\sin 2x}{2} + \frac{(2\cos^2 x - 1)^2}{2} + \frac{1}{8} has a stationary point PP in the range 0xπ60 \leq x \leq \frac{\pi}{6}
(c) Find the exact coordinates of PP
(7)

1.26: 3D angles in a pyramid

4PM1/1/November/2023 — Question 6 · 11 marks

1.26 diagram 1
Figure 3 shows a right pyramid with a horizontal square base.
AB=BC=CD=DA=xcmAB = BC = CD = DA = x \mathrm{cm}
AV=BV=CV=DV=xcmAV = BV = CV = DV = x \mathrm{cm}
OO is the point of intersection of the diagonals of the base.
The vertex VV of the pyramid is vertically above OO
(a) Show that VO=22xcmVO = \frac{\sqrt{2}}{2}x \mathrm{cm}
(3)
(b) Find, in degrees, the size of the angle AVCAVC
(2)
(c) Find, in degrees to one decimal place, the size of the angle between the plane VABVAB and the plane VDCVDC
(3)
The volume of the pyramid is 200cm3200 \mathrm{cm}^3
Given that the volume of a pyramid =13×base area×height= \frac{1}{3} \times \text{base area} \times \mathrm{height}
(d) Find to 3 significant figures, the value of xx
(3)

1.27: Circular measure and sectors, trigonometric identities and trigonometric equations

4PM1/1/November/2023 — Question 10 · 17 marks

(a) Using formulae on page 2, show that
(i)sin2A=2sinAcosA(i) \mathrm{sin} 2A = 2 \mathrm{sin} A \mathrm{cos} A
(ii)cos2A=2cos2A1(ii) \mathrm{cos} 2A = 2 \mathrm{cos}^2 A - 1
(3)
f(θ)=2tanθ1+tan2θf(\theta) = \frac{2 \mathrm{tan} \theta}{1 + \mathrm{tan}^2 \theta}
(b) Show that f(θ)=sin2θf(\theta) = \mathrm{sin} 2\theta
(4)
(c) Solve, in radians to 3 significant figures, for π2xπ2-\frac{\pi}{2} \leq x \leq \frac{\pi}{2}, the equation
5tan(x+π6)=[1+tan2(x+π6)][12cos2(x+π6)]5 \mathrm{tan}\left(x + \frac{\pi}{6}\right) = \left[1 + \mathrm{tan}^2\left(x + \frac{\pi}{6}\right)\right] \left[1 - 2 \mathrm{cos}^2\left(x + \frac{\pi}{6}\right)\right]
(6)
(d) Using calculus, find the exact value of
0π2(4tanθ1+tan2θcos5θ+2)dθ\int_0^{\frac{\pi}{2}} \left( \frac{4 \mathrm{tan} \theta}{1 + \mathrm{tan}^2 \theta} - \mathrm{cos} 5\theta + 2 \right) \mathrm{d}\theta
(4)

1.30: Trigonometric identities

4PM1/1/June/2023 — Question 9 · 13 marks

(a) Using the formulae on page 2, show that
(i)cos2A=cos2A+12(i) \mathrm{cos}^2 A = \frac{\mathrm{cos} 2A + 1}{2}
(ii)sin2A=1cos2A2(ii) \mathrm{sin}^2 A = \frac{1 - \mathrm{cos} 2A}{2}
(4)
(b) Show that
(2sinxcosx)(sinx3cosx)=12(cos2x7sin2x+5)(2 \mathrm{sin} x - \mathrm{cos} x)(\mathrm{sin} x - 3 \mathrm{cos} x) = \frac{1}{2} (\mathrm{cos} 2x - 7 \mathrm{sin} 2x + 5)
(5)
y=(2sinxcosx)(sinx3cosx)y = (2 \mathrm{sin} x - \mathrm{cos} x)(\mathrm{sin} x - 3 \mathrm{cos} x)
(c) Solve, for 0x1800^\circ \leq x \leq 180^\circ the equation, dydx=0\frac{\mathrm{d}y}{\mathrm{d}x} = 0
Give your answers to the nearest whole number.
(4)

1.31: Sector geometry and area

4PM1/1R/June/2023 — Question 3 · 9 marks

1.31 diagram 1
Figure 2 shows triangle ABCABC where
AB=10cm,AC=8cm,BC=xcmandBAC=100AB = 10 \mathrm{cm}, \quad AC = 8 \mathrm{cm}, \quad BC = x \mathrm{cm} \quad \mathrm{and} \quad \angle BAC = 100^\circ
(a) Find, to 3 significant figures, the value of xx
(2)
(b) Find, in degrees to one decimal place, the size of
(i) angle ABCABC
(3)
(ii) angle ACBACB
The bisector of angle ABCABC meets ACAC at the point MM
(c) Find the area, in cm2\mathrm{cm}^2 to 3 significant figures, of triangle BMCBMC.
(4)

1.28: Areas using trigonometry

4PM1/2/November/2023 — Question 2 · 7 marks

In triangle ABCABC, AB=3xAB = 3x cm, BC=5xBC = 5x cm and ABC=110\angle ABC = 110^\circ
(a) Find, in degrees to one decimal place, the size of BCA\angle BCA
(4)
The area of triangle ABCABC is 24cm224 \mathrm{cm}^2
(b) Find, to 3 significant figures, the value of xx
(3)

1.29: Circular measure and sectors and areas using trigonometry

4PM1/2/November/2023 — Question 9 · 13 marks

1.29 diagram 1
A logo, AEBCDAEBCD, is shown shaded in Figure 2.
The straight line ABCABC is the diameter of the semicircle ADCADC
AEBAEB is an arc of a circle with centre OO
All angles are measured in radians.
BC=2xBC = 2x cm
OA=OB=xOA = OB = x cm
• length of arc AEB=1.8xAEB = 1.8x cm
The perimeter of the logo is PP
(a) Show that P=ax(π+πsin0.9+b)P = ax(\pi + \pi \mathrm{sin} 0.9 + b) where aa and bb are constants to be found.
(7)
Given that x=10x = 10 cm,
(b) find, in cm2\mathrm{cm}^2 to 3 significant figures, the area of the logo.
(6)

1.32: Sector geometry and area

4PM1/2/June/2023 — Question 3 · 6 marks

1.32 diagram 1
Figure 1 shows a circle, centre OO, with radius rr cm.
The points AA, PP and BB lie on the circle.
The obtuse angle AOB=θAOB = \theta radians.
The area of the sector APBOAPBO, shown shaded, is 372.4cm2372.4 \mathrm{cm}^2 and the length of the arc APBAPB is 53.2cm53.2 \mathrm{cm}.
Find, to 3 significant figures where appropriate, the value of
(i) rr
(ii) θ\theta
(6)

1.33: 3D angles in a pyramid

4PM1/2/June/2023 — Question 9 · 6 marks

1.33 diagram 1
Figure 4 shows a right pyramid with vertex VV and base ABCDEABCDE which is a regular pentagon.
AB=BC=CD=DE=EA=2xcmAB = BC = CD = DE = EA = 2x \mathrm{cm}
VA=VB=VC=VD=VE=3xcmVA = VB = VC = VD = VE = 3x \mathrm{cm}
Find, in degrees to one decimal place, the size of the angle between the plane VBCVBC and the base ABCDEABCDE
(6)

1.35: Trigonometric identities and equations

4PM1/2R/June/2023 — Question 11 · 12 marks

(a) Use a formula on page 2 to show that sin2A=12(1cos2A)\mathrm{sin}^2 A = \frac{1}{2}(1 - \mathrm{cos} 2A)
(3)
(b) Show that sin4x+cos4x=3+cos4x4\mathrm{sin}^4 x + \mathrm{cos}^4 x = \frac{3 + \mathrm{cos} 4x}{4}
(5)
(c) Hence solve, in degrees to one decimal place, the equation
8sin4(θ2)+8cos4(θ2)=5sin(2θ)+6for0θ<1808\mathrm{sin}^4\left(\frac{\theta}{2}\right) + 8\mathrm{cos}^4\left(\frac{\theta}{2}\right) = 5\mathrm{sin}(2\theta) + 6 \quad \mathrm{for} 0^\circ \leq \theta < 180^\circ
(4)

1.36: Area in a rectangle using trigonometry

4PM1/1/June/2022 — Question 3 · 7 marks

1.36 diagram 1
Figure 2 shows a rectangle ABCDABCD with AB=10cmAB=10\,\mathrm{cm} and AD=15cmAD=15\,\mathrm{cm}. EE is the point inside the rectangle such that DE=13cmDE=13\,\mathrm{cm} and BAE=35\angle BAE=35^\circ.
Given that AED\angle AED is obtuse, find the area, in cm2\mathrm{cm}^2 to one decimal place, of triangle BCEBCE.
(7)

1.37: A sector and a shaded area

4PM1/1R/June/2022 — Question 3 · 6 marks

1.37 diagram 1
Figure 1 shows sector ORSORS of a circle with centre OO and radius 4cm4\,\mathrm{cm}. The size of angle ROSROS is θ\theta radians. The area of sector ORSORS is 2πcm22\pi\,\mathrm{cm}^2.
(a) Find the exact value of θ\theta.
(2)
(b) Find the perimeter, in cm\mathrm{cm} to 3 significant figures, of the sector ORSORS.
(2)
The point TT lies on OROR such that OT:TR=1:3OT:TR=1:3. The shaded region is bounded by TRTR, TSTS and the arc RSRS. The area of this region is Acm2A\,\mathrm{cm}^2.
(c) Find the exact value of AA.
(2)

1.38: Exact values involving surds and trigonometry

4PM1/1R/June/2022 — Question 6 · 8 marks

Given that
a+552=11+55,\frac{a+\sqrt{5}}{\sqrt{5}-2}=11+5\sqrt{5},
(a) without using a calculator, find the value of aa.
Show your working clearly.
(2)
Triangle PQRPQR is such that
PR=(x+3)cm,QR=xcm,PR=(x+3)\,\mathrm{cm}, \qquad QR=x\,\mathrm{cm},
QPR=30,PQR=45.\angle QPR=30^\circ, \qquad \angle PQR=45^\circ.
(b) Show that
x=3+32.x=3+3\sqrt{2}.
(3)
Given that
sin105=6+24\mathrm{sin}\,105^\circ=\frac{\sqrt{6}+\sqrt{2}}{4}
and that the area of triangle PQRPQR is Acm2A\,\mathrm{cm}^2,
(c) find the exact value of AA in the form
98(p6+q2+r3+s),\frac{9}{8}\left(p\sqrt{6}+q\sqrt{2}+r\sqrt{3}+s\right),
where pp, qq, rr and ss are integers.
(3)

1.39: Trigonometric identities and areas using trigonometry

4PM1/1R/June/2022 — Question 10 · 11 marks

1.39 diagram 1
Using suitable results for sin(A+B)\mathrm{sin}\,(A+B) and sin(AB)\mathrm{sin}\,(A-B),
(a) show that
2sin4xcosx=sin5x+sin3x.2\mathrm{sin}\,4x\,\mathrm{cos}\,x=\mathrm{sin}\,5x+\mathrm{sin}\,3x.
(3)
Figure 4 shows a sketch of part of the curve with equation
y=6sin4xcosx.y=6\mathrm{sin}\,4x\,\mathrm{cos}\,x.
(b) Use calculus to find the total area of the regions bounded by the curve and the xx-axis between x=0x=0 and x=π2x=\frac{\pi}{2}.
Give your answer to 3 significant figures.
(8)

1.40: Exact area enclosed by two circles

4PM1/2/June/2022 — Question 4 · 7 marks

1.40 diagram 1
Figure 1 shows two circles, C1C_1 and C2C_2, each with a radius of 6cm6\,\mathrm{cm}.
The centre of C1C_1 is O1O_1 such that O1O_1 lies on C2C_2. The centre of C2C_2 is O2O_2 such that O2O_2 lies on C1C_1.
The circles intersect at the points AA and BB and enclose the region RR, shown shaded in Figure 1.
The area of region RR is Pcm2P\,\mathrm{cm}^2.
Find the exact value of PP, giving your answer in the form
aπbc,a\pi-b\sqrt{c},
where aa, bb and cc are integers.
(7)

1.41: Trigonometric identities and equations

4PM1/2/June/2022 — Question 7 · 11 marks

(i) (a) Using a formula from page 2, show that
tan2θ=2tanθ1tan2θ.\mathrm{tan}\,2\theta = \frac{2\mathrm{tan}\,\theta}{1-\mathrm{tan}^2\theta}.
(2)
Given that tan2α=1\mathrm{tan}\,2\alpha=1,
(b) show that
tanα=a±b,\mathrm{tan}\,\alpha=a\pm\sqrt{b},
where aa and bb are integers whose values need to be found.
(3)
(ii) (a) Using formulae from page 2, show that
cos(x30)=sin(x+30)\mathrm{cos}\,(x-30)^\circ=\mathrm{sin}\,(x+30)^\circ
can be written as tanx=1\mathrm{tan}\,x^\circ=1.
(4)
(b) Hence, or otherwise, solve
cos(2y30)=sin(2y+30)\mathrm{cos}\,(2y-30)^\circ=\mathrm{sin}\,(2y+30)^\circ
for 90<y90-90<y\leq90.
(2)

1.42: Angle between a face of a pyramid and its base

4PM1/2R/June/2022 — Question 6 · 6 marks

1.42 diagram 1
Figure 1 shows a right pyramid VABCDVABCD with vertex VV and square base ABCDABCD. Each of the edges of the pyramid has the same length.
Find the size, in degrees to one decimal place, of the angle between the plane CVDCVD and the base ABCDABCD.
(6)

1.43: Trigonometric equations

4PM1/2R/June/2022 — Question 7 · 12 marks

Solve
(a) cos(3x15)=32,0x<180,\mathrm{cos}\,(3x-15)^\circ=\frac{\sqrt{3}}{2}, \qquad 0\leq x<180,
(4)
(b) 3tany+4siny=0,180y<180,3\mathrm{tan}\,y^\circ+4\mathrm{sin}\,y^\circ=0, \qquad -180\leq y<180,
giving your answers to one decimal place where appropriate,
(4)
(c) cosθ=3sin2θ1,180θ<180,\mathrm{cos}\,\theta^\circ=3\mathrm{sin}^2\theta^\circ-1, \qquad -180\leq\theta<180,
giving your answers to one decimal place where appropriate.
(4)

1.44: Exact trigonometric values and an addition formula

4PM1/1/June/2021 — Question 2 · 6 marks

Angle α\alpha is acute such that cosα=35\mathrm{cos}\,\alpha=\frac35.
Angle β\beta is obtuse such that sinβ=12\mathrm{sin}\,\beta=\frac12.
(a) Find the exact value of
(i) tanα\mathrm{tan}\,\alpha,
(ii) tanβ\mathrm{tan}\,\beta.
(3)
(b) Hence show that
tan(α+β)=m3nn3+m,\mathrm{tan}(\alpha+\beta)=\frac{m\sqrt3-n}{n\sqrt3+m},
where mm and nn are positive integers whose values are to be found.
(3)

1.45: A sector and tangents to a circle

4PM1/2/June/2021 — Question 3 · 9 marks

1.45 diagram 1
1.45 diagram 2
Figure 1 shows a sector OPQOPQ of a circle with centre OO. The radius of the circle is 18cm18\,\mathrm{cm} and the angle POQPOQ is 2π3\frac{2\pi}{3} radians.
(a) Find the length of the arc PQPQ, giving your answer as a multiple of π\pi.
(2)
Figure 2 shows the sector OPQOPQ and the kite OPTQOPTQ. PTPT is the tangent to the circle at PP and QTQT is the tangent at QQ, such that angle PTQ=αPTQ=\alpha radians.
(b) (i) Find α\alpha in terms of π\pi.
(1)
(ii) Calculate, to 3 significant figures, the area of the region, shown shaded in Figure 2, which is bounded by the arc PQPQ and the tangents PTPT and QTQT.
(6)

1.46: Trigonometric identities and equations

4PM1/2/June/2021 — Question 10 · 10 marks

(a) Solve the equation
tanx=3for0x<360.\mathrm{tan}\,x^\circ=-3 \qquad \text{for} \qquad 0\leq x<360.
Give your solutions to the nearest whole number.
(3)
Given that
7sin2θ+sinθcosθ=6,7\mathrm{sin}^2\theta+\mathrm{sin}\,\theta\,\mathrm{cos}\,\theta=6,
(b) show that
tan2θ+tanθ6=0.\mathrm{tan}^2\theta+\mathrm{tan}\,\theta-6=0.
(3)
(c) Hence solve the equation
7sin2y+sinycosy=6for0y<360.7\mathrm{sin}^2y^\circ+\mathrm{sin}\,y^\circ\,\mathrm{cos}\,y^\circ=6 \qquad \text{for} \qquad 0\leq y<360.
Give your solutions to the nearest whole number.
(4)

1.47: Angles in a right pyramid

4PM1/1/November/2020 — Question 3 · 9 marks

1.47 diagram 1
Figure 1 shows the right pyramid ABCDEABCDE. Its base ABCDABCD is a horizontal rectangle with AD=12cmAD=12\,\mathrm{cm} and CD=16cmCD=16\,\mathrm{cm}. The height MEME is 14cm14\,\mathrm{cm}, where MM is the point of intersection of the diagonals of the base. The sloping edges are all of equal length.
(a) Calculate, to 3 significant figures, the length of a sloping edge.
(3)
Calculate, in degrees to one decimal place, the size of
(b) the angle between AEAE and the base,
(3)
(c) the angle between the plane AEDAED and the base.
(3)

1.48: Cosine and sine rules in a triangle

4PM1/1/November/2020 — Question 9 · 12 marks

1.48 diagram 1
Figure 3 shows triangle ABCABC with AB=12cmAB=12\,\mathrm{cm}, BC=6cmBC=6\,\mathrm{cm} and AC=2xcmAC=2x\,\mathrm{cm}. The point DD is the midpoint of ACAC and BD=6cmBD=6\,\mathrm{cm}.
ABD=θ\angle ABD=\theta^\circ and DBC=ϕ\angle DBC=\phi^\circ, where θ0\theta\neq0 and ϕ0\phi\neq0.
(a) Show that
cosADB=x210812x.\mathrm{cos}\,ADB=\frac{x^2-108}{12x}.
(2)
(b) Hence, or otherwise, show that
AC=66cm.AC=6\sqrt6\,\mathrm{cm}.
(4)
(c) Show that
sin(θ+ϕ)=sinϕ.\mathrm{sin}(\theta^\circ+\phi^\circ)=\mathrm{sin}\,\phi^\circ.
(4)
(d) Hence show that
θ=1802ϕ.\theta=180-2\phi.
(2)

1.49: Exact trigonometric values

4PM1/1R/November/2020 — Question 1 · 7 marks

Here is a formula
P=3+2sin(3πt8),0t12.P=3+2\mathrm{sin}\left(\frac{3\pi t}{8}\right), \qquad 0\leq t\leq12.
(a) Find the exact value of PP when t=103t=\frac{10}{3}.
(2)
(b) Find
(i) the largest value of PP,
(ii) the smallest value of PP.
(2)
(c) Find the least value of tt for which P=4P=4.
(3)

1.50: A trigonometric identity and a definite integral

4PM1/1R/November/2020 — Question 6 · 7 marks

(a) Show that
sin(A+B)+sin(AB)=2sinAcosB.\mathrm{sin}(A+B)+\mathrm{sin}(A-B)=2\mathrm{sin}\,A\,\mathrm{cos}\,B.
(2)
(b) Hence express 2sin7xcosx2\mathrm{sin}\,7x\,\mathrm{cos}\,x in the form
sinmx+sinnx,\mathrm{sin}\,mx+\mathrm{sin}\,nx,
where mm and nn are integers, giving the value of mm and the value of nn.
(1)
(c) Use calculus to evaluate
0π46sin7xcosxdx.\int_0^{\frac{\pi}{4}}6\mathrm{sin}\,7x\,\mathrm{cos}\,x\,\mathrm{d}x.
(4)

1.51: Trigonometric equations

4PM1/1R/November/2020 — Question 10 · 11 marks

Solve
(a) sin(x+π3)=32,0x2π,\mathrm{sin}\left(x+\frac{\pi}{3}\right)=\frac{\sqrt{3}}{2}, \qquad 0\leq x\leq2\pi,
giving your answers in terms of π\pi,
(3)
(b) 3sinθ+5cosθ=0,360θ360,3\mathrm{sin}\,\theta+5\mathrm{cos}\,\theta=0, \qquad -360^\circ\leq\theta\leq360^\circ,
giving your answers to the nearest degree,
(3)
(c) 1+sin2y=2cos22y,180y0.1+\mathrm{sin}\,2y=2\mathrm{cos}^2 2y, \qquad -180^\circ\leq y\leq0^\circ.
(5)

1.52: Compound-angle identities, equations and integration

4PM1/2/November/2020 — Question 10 · 16 marks

(a) Show that
cos(A+B)+cos(AB)=2cosAcosB.\mathrm{cos}\,(A+B)+\mathrm{cos}\,(A-B)=2\mathrm{cos}\,A\,\mathrm{cos}\,B.
(2)
(b) Hence show that
cosP+cosQ=2cos(P+Q2)cos(PQ2).\mathrm{cos}\,P+\mathrm{cos}\,Q =2\mathrm{cos}\left(\frac{P+Q}{2}\right) \mathrm{cos}\left(\frac{P-Q}{2}\right).
(3)
(c) Solve, for 0θπ20\leq\theta\leq\frac{\pi}{2}, the equation
cos5θ+cos7θ=0.\mathrm{cos}\,5\theta+\mathrm{cos}\,7\theta=0.
Give each solution in terms of π\pi.
(4)
(d) Show that
cos8x+2cos6x+cos4x=4cos6xcos2x.\mathrm{cos}\,8x+2\mathrm{cos}\,6x+\mathrm{cos}\,4x =4\mathrm{cos}\,6x\,\mathrm{cos}^2x.
(3)
(e) Use calculus to find the exact value of
0π3cos6xcos2xdx.\int_0^{\frac{\pi}{3}}\mathrm{cos}\,6x\,\mathrm{cos}^2x\,\mathrm{d}x.
(4)

1.53: Length and area in a triangle

4PM1/2R/November/2020 — Question 3 · 8 marks

1.53 diagram 1
Figure 1 shows triangle ABCABC in which AB=10cmAB=10\,\mathrm{cm} and AC=12cmAC=12\,\mathrm{cm}. The point DD lies on BCBC such that BD=6cmBD=6\,\mathrm{cm}, DC=2cmDC=2\,\mathrm{cm} and AD=xcmAD=x\,\mathrm{cm}.
(a) Show that x=11x=11.
(4)
(b) Find the area, in cm2\mathrm{cm}^2 to 3 significant figures, of triangle ADBADB.
(4)

1.54: Tangents and the area outside a sector

4PM1/2R/November/2020 — Question 5 · 8 marks

1.54 diagram 1
In Figure 2, ABAB and ACAC are tangents to a circle with centre OO and radius rcmr\,\mathrm{cm}.
The points BB and CC lie on the circle so that OBCOBC is a sector of this circle and
BOC=2π3 radians.\angle BOC=\frac{2\pi}{3}\ \text{radians}.
Given that the area of the shaded region is 10cm210\,\mathrm{cm}^2, find, to 3 significant figures, the value of rr.
(8)

1.55: Sine rule: angle and area of a triangle

4PM1/1/June/2019 — Question 3 · 6 marks

In triangle ABCABC, AC=7cmAC=7\,\mathrm{cm}, BC=10cmBC=10\,\mathrm{cm} and angle BAC=65BAC=65^{\circ}.
(a) Find, to the nearest 0.10.1^{\circ}, the size of angle ABCABC.
(3)
(b) Find, in cm2\mathrm{cm}^{2} to 3 significant figures, the area of triangle ABCABC.
(3)

1.56: Sector: angle and perimeter of a shaded region

4PM1/1/June/2019 — Question 4 · 6 marks

1.56 diagram 1
Figure 1 shows a sector OABOAB of a circle where angle AOB=θAOB=\theta radians. The circle has centre OO and radius 15cm15\,\mathrm{cm}. The point CC divides OAOA in the ratio 2:12:1 and the point DD divides OBOB in the ratio 2:12:1.
The area of the region ABDCABDC, shown shaded in Figure 1, is 100cm2100\,\mathrm{cm}^{2}.
Find
(a) the value of θ\theta,
(3)
(b) the perimeter of the region ABDCABDC.
(3)

1.57: Trigonometric equations and an identity

4PM1/1/June/2019 — Question 7 · 12 marks

(a) Solve, in degrees to one decimal place,
(3cosθ+5)(5sinθ3)=0for 0θ<180(3\cos\theta+5)(5\sin\theta-3)=0\qquad\text{for }0\leqslant\theta<180^{\circ}
(2)
(b) Show that the equation
8sin(xα)=3sin(x+α)8\sin(x-\alpha)=3\sin(x+\alpha)
can be written in the form
5tanx=11tanα5\tan x=11\tan\alpha
(5)
(c) Hence solve, to one decimal place,
8sin(2y30)=3sin(2y+30)for 0y<1808\sin(2y-30^{\circ})=3\sin(2y+30^{\circ})\qquad\text{for }0\leqslant y<180^{\circ}
(5)

1.66: Trigonometric form and triangle ABC

4PM1/1/January/2019 — Question 4 · 11 marks

1.66 diagram 1
sin(A+B)=sinAcosB+sinBcosA\sin(A+B)=\sin A\cos B+\sin B\cos A
tanA=sinAcosA\tan A=\frac{\sin A}{\cos A}
(a) Show that the equation asin(x30)=bsin(x+30)a\sin(x-30)^{\circ}=b\sin(x+30)^{\circ} can be written in the form
tanx=a+b3(ab).\tan x^{\circ}=\frac{a+b}{\sqrt{3}(a-b)}.
(5)
In triangle ABCABC, AC=6cmAC=6\,\mathrm{cm}, BC=14cmBC=14\,\mathrm{cm}, ABC=(x30)\angle ABC=(x-30)^{\circ} and BAC=(x+30)\angle BAC=(x+30)^{\circ} as shown in Figure 2.
(b) Find, in degrees to 1 decimal place, the size of ACB\angle ACB.
(4)
(c) Find, to 3 significant figures, the area of triangle ABCABC.
(2)

1.58: Perimeter and area of a sector

4PM1/1R/June/2019 — Question 1 · 3 marks

1.58 diagram 1
Figure 1 shows sector AOBAOB of a circle with centre OO and radius rcmr\,\mathrm{cm}.
The angle AOBAOB is 1.51.5 radians and the length of arc ABAB is 12cm12\,\mathrm{cm}.
Calculate
(a) the value of rr,
(1)
(b) the area of the sector AOBAOB.
(2)

1.59: Triangle ABC: sine rule and area

4PM1/1R/June/2019 — Question 2 · 6 marks

1.59 diagram 1
Figure 2 shows triangle ABCABC in which
AB=2xcmAC=3xcmBC=4xcmAB=2x\,\mathrm{cm}\qquad AC=3x\,\mathrm{cm}\qquad BC=4x\,\mathrm{cm}
(a) Show that sinABC=31516\sin ABC=\dfrac{3\sqrt{15}}{16}.
(4)
Given that the area of triangle ABCABC is 751564cm2\dfrac{75\sqrt{15}}{64}\,\mathrm{cm}^{2},
(b) find the value of xx.
(2)

1.61: Cosine rule to find x

4PM1/2/June/2019 — Question 4 · 5 marks

In triangle ABCABC, AB=5xcmAB=5x\,\mathrm{cm}, BC=(3x1)cmBC=(3x-1)\,\mathrm{cm}, AC=(2x+5)cmAC=(2x+5)\,\mathrm{cm} and angle ABC=60ABC=60^{\circ}.
Find, to 3 significant figures, the value of xx.
(5)

1.62: Pyramid with a square base: lengths and angles

4PM1/2/June/2019 — Question 11 · 16 marks

1.62 diagram 1
Figure 1 shows a right pyramid with vertex VV and square base, ABCDABCD, of side 16cm16\,\mathrm{cm}.
The size of angle AVCAVC is 9090^{\circ}.
(a) Show that the height of the pyramid is 82cm8\sqrt{2}\,\mathrm{cm}.
(4)
(b) Find, in cm, the length of VAVA.
(3)
(c) Find, in cm, the exact length of the perpendicular from DD onto VAVA.
(3)
Find, in degrees to one decimal place, the size of
(d) the angle between the plane VABVAB and the base ABCDABCD,
(3)
(e) the obtuse angle between the plane VABVAB and the plane VADVAD.
(3)

1.67: Angles in a triangular pyramid

4PM1/2/January/2019 — Question 5 · 10 marks

1.67 diagram 1
Figure 1 shows a triangular pyramid ABCDABCD where triangle ABCABC is the base and BDBD is perpendicular to the base.
AB=15cm,AC=510cm,BC=5cm,BD=10cmAB=15\,\mathrm{cm},\qquad AC=5\sqrt{10}\,\mathrm{cm},\qquad BC=5\,\mathrm{cm},\qquad BD=10\,\mathrm{cm}
(a) Show that ABC=90\angle ABC=90^{\circ}.
(2)
(b) Find, in degrees to 1 decimal place, the size of DAC\angle DAC.
(4)
The point XX on ACAC is such that BXBX is perpendicular to ACAC.
(c) Find, in degrees to 1 decimal place, the size of DXB\angle DXB.
(4)

1.68: Double-angle identity, equation and integral

4PM1/2/January/2019 — Question 11 · 17 marks

cos(A+B)=cosAcosBsinAsinB\cos(A+B)=\cos A\cos B-\sin A\sin B
(a) (i) Using the above identity, show that
cos2x=12sin2x.\cos 2x=1-2\sin^{2}x.
(ii) Hence show that
13sinx2cos2x104sinx3=4+sinx.\frac{13\sin x-2\cos 2x-10}{4\sin x-3}=4+\sin x.
(7)
(b) Hence solve, in radians to 3 significant figures, the equation
10+2cos(2θ+π3)13sin(θ+π6)=2sin(θ+π6)+810+2\cos\left(2\theta+\frac{\pi}{3}\right)-13\sin\left(\theta+\frac{\pi}{6}\right)=2\sin\left(\theta+\frac{\pi}{6}\right)+8
for πθ2π\pi\leqslant\theta\leqslant 2\pi.
(5)
(c) Find the exact value of
0π/213sinx2cos2x10+4xsinx3x4sinx3dx.\int_{0}^{\pi/2}\frac{13\sin x-2\cos 2x-10+4x\sin x-3x}{4\sin x-3}\,\mathrm{d}x.
(5)

1.63: Right prism with triangular cross-section

4PM1/2R/June/2019 — Question 8 · 13 marks

1.63 diagram 1
Figure 3 shows a right prism ABCDEFABCDEF. The cross section BCFBCF of the prism is a triangle.
AB=DC=12 cmBC=AD=8 cmBF=AE=10 cmFBC=EAD=60AB=DC=12\ \mathrm{cm} \qquad BC=AD=8\ \mathrm{cm} \qquad BF=AE=10\ \mathrm{cm} \qquad \angle FBC=\angle EAD=60^{\circ}
The point NN lies on BCBC such that FNFN is perpendicular to BCBC.
(a) Show that BN=5 cmBN=5\ \mathrm{cm}.
(2)
(b) Find, in cm\mathrm{cm} to 3 significant figures, the length of ENEN.
(3)
The midpoint of BFBF is XX and the midpoint of FCFC is YY.
(c) Find, in degrees to one decimal place, the size of the angle between the plane ABCDABCD and the plane AXYDAXYD.
(2)
(d) Find, in degrees to one decimal place, the size of the angle AYEAYE.
(6)

1.64: Multiple angle cosine identities and integration

4PM1/2R/June/2019 — Question 10 · 15 marks

(a) Use the formula for cos(A+B)\cos(A+B) to show that cos2A=2cos2A1\cos 2A=2\cos^2 A-1
(2)
(b) Show that cos4A=8cos4A8cos2A+1\cos 4A=8\cos^4 A-8\cos^2 A+1
(4)
(c) Solve the equation
cos2(θ4+π24)[cos2(θ4+π24)1]=1160θ<2π\cos^2\left(\dfrac{\theta}{4}+\dfrac{\pi}{24}\right)\left[\cos^2\left(\dfrac{\theta}{4}+\dfrac{\pi}{24}\right)-1\right]=-\dfrac{1}{16} \qquad 0 \leqslant \theta < 2\pi
Give your answers in terms of π\pi.
(5)
f(A)=4cos4A4cos2A+1f(A)=4\cos^4 A-4\cos^2 A+1
(d) Using calculus, find the exact value of π6π2f(A)dA\displaystyle\int_{\frac{\pi}{6}}^{\frac{\pi}{2}} f(A)\,\mathrm{d}A
Give your answer in the form aπbca\pi-b\sqrt{c} where aa and bb are fractions in their lowest terms and cc is a prime number.
(4)

1.79: Trigonometric identities and areas using trigonometry

4PM1/1/January/2018 — Question 6 · 11 marks

1.79 diagram 1
Figure 1 shows the triangle ABCABC with AB=x cmAB=x\text{ cm}, BC=(2x2) cmBC=(2x-2)\text{ cm}, AC=(x+4) cmAC=(x+4)\text{ cm} and BAC=θ\angle BAC=\theta^\circ.
Given that tanθ=255\tan\theta^\circ=\sqrt{255} and without finding the value of θ\theta,
(a) show that cosθ=116\cos\theta^\circ=\dfrac1{16}. (2)
Hence find
(b) the value of xx, (5)
(c) the size, in degrees to 1 decimal place, of ABC\angle ABC, (2)
(d) the area, in cm2\text{cm}^2 to 3 significant figures, of triangle ABCABC. (2)

1.80: Trigonometric identities, trigonometric equations and exact trigonometric values

4PM1/1/January/2018 — Question 10 · 16 marks

cos(A+B)=cosAcosBsinAsinB\cos(A+B)=\cos A\cos B-\sin A\sin B
(a) Show that cos2θ=12(cos2θ+1)\cos^2\theta=\dfrac12(\cos2\theta+1). (3)
Given that f(θ)=8cos4θ+8sin2θ7f(\theta)=8\cos^4\theta+8\sin^2\theta-7
(b) show that f(θ)=cos4θf(\theta)=\cos4\theta. (5)
(c) Solve, for 0θπ20\le\theta\le\dfrac\pi2, the equation
16cos4(θπ6)+16sin2(θπ6)15=016\cos^4\left(\theta-\dfrac\pi6\right)+16\sin^2\left(\theta-\dfrac\pi6\right)-15=0
(4)
(d) Using calculus, find the exact value of
0π/2(8cos4θ+8sin2θ+2sin2θ)dθ\displaystyle\int_0^{\pi/2}(8\cos^4\theta+8\sin^2\theta+2\sin2\theta)\,d\theta
(4)

1.83: Sector geometry and area

4PM1/1/June/2018 — Question 1 · 4 marks

1.83 diagram 1
Figure 1 shows a sector OABOAB of a circle. The circle has centre OO and radius 10 cm. The area of the sector is 25 cm225\text{ cm}^2 and angle AOB=θAOB=\theta radians.
Find
(a) the value of θ\theta, (2)
(b) the length of the arc ABAB. (2)

1.84: Areas using trigonometry

4PM1/1/June/2018 — Question 3 · 8 marks

In triangle ABCABC, AB=12 cmAB=12\text{ cm}, BC=9 cmBC=9\text{ cm} and angle BAC=42BAC=42^\circ.
(a) Find, in degrees to the nearest 0.10.1^\circ, each of the two possible sizes of angle ABCABC. (5)
(b) Find, to 2 significant figures, the smaller of the two possible areas of triangle ABCABC. (3)

1.85: 3D angles in a pyramid

4PM1/1/June/2018 — Question 11 · 14 marks

1.85 diagram 1
Figure 3 shows the right pyramid ABCDEABCDE. The base of the pyramid, ABCDABCD, is a rectangle with CD=16x cmCD=16x\text{ cm} and AD=12x cmAD=12x\text{ cm}. The diagonals of the base intersect at the point XX. The edges EA,EB,ECEA,EB,EC and EDED are all of equal length. The size of the angle between EAEA and the base ABCDABCD is 4545^\circ.
Find, in terms of xx,
(a) the height, EXEX, of the pyramid, (3)
(b) the length of EAEA. (2)
Find, in degrees to the nearest 0.10.1^\circ, the size of
(c) the acute angle between the planes AEBAEB and ABCDABCD, (3)
(d) the acute angle between the planes BEDBED and AECAEC. (3)
The area of triangle AEDAED is 250 cm2250\text{ cm}^2.
(e) Find, to 4 significant figures, the value of xx. (3)

1.81: Sector geometry and area

4PM1/2/January/2018 — Question 1 · 4 marks

1.81 diagram 1
Figure 1 shows the sector AOBAOB of a circle with centre OO and radius 12 cm. The angle AOBAOB is θ\theta radians and the area of the sector is 192 cm2192\text{ cm}^2.
Calculate
(a) the value of θ\theta, (2)
(b) the length, in cm, of the arc ABAB. (2)

1.82: Trigonometric identities

4PM1/2/January/2018 — Question 11 · 12 marks

1.82 diagram 1
A pyramid with a rectangular base ABCDABCD and vertex EE is shown in Figure 6.
The rectangular base is horizontal with AB=12 cmAB=12\text{ cm} and BC=8 cmBC=8\text{ cm}. The diagonals of the base intersect at the point OO. The vertex EE of the pyramid is vertically above OO. The height of the pyramid is hh cm and AE=BE=CE=DE=10 cmAE=BE=CE=DE=10\text{ cm}.
(a) Show that h=43h=4\sqrt3. (3)
(b) Find, in degrees to 1 decimal place, the size of angle OCEOCE. (2)
The angle between OEOE and the plane CBECBE is θ\theta^\circ.
(c) Show that cosθ=277\cos\theta^\circ=\dfrac{2\sqrt7}7. (3)
The point PP is the midpoint of BEBE and the point QQ is the midpoint of CECE.
(d) Find, in degrees to 1 decimal place, the size of the angle between the plane OPQOPQ and the plane EPQEPQ. (4)

1.87: Trigonometric identities, trigonometric equations and exact trigonometric values

4PM1/2/June/2018 — Question 8 · 16 marks

cos(A+B)=cosAcosBsinAsinB\cos(A+B)=\cos A\cos B-\sin A\sin B
sin(A+B)=sinAcosB+cosAsinB\sin(A+B)=\sin A\cos B+\cos A\sin B
Using the above identities
(a) show that
(i) cos2θ=12sin2θ\cos2\theta=1-2\sin^2\theta
(ii) sin2θ=2sinθcosθ\sin2\theta=2\sin\theta\cos\theta (3)
f(θ)=cos4θ+2cos2θf(\theta)=\cos4\theta+2\cos2\theta
(b) Show that f(θ)=8sin4θ12sin2θ+3f(\theta)=8\sin^4\theta-12\sin^2\theta+3. (4)
(c) Solve, giving your solutions to 3 significant figures, the equation
4sin4x6sin2xcos2x+1.2=0,0x<904\sin^4x^\circ-6\sin^2x^\circ-\cos2x^\circ+1.2=0,\qquad 0\le x<90
(4)
(d) (i) Find (2sin4θ3sin2θ)dθ\displaystyle\int(2\sin^4\theta-3\sin^2\theta)\,d\theta
(ii) Hence find the exact value of 0π/3(2sin4θ3sin2θ)dθ\displaystyle\int_0^{\pi/3}(2\sin^4\theta-3\sin^2\theta)\,d\theta.
Give your answer in the form abcπa\sqrt b-c\pi where aa and cc are rational numbers and bb is a prime number. (5)

1.69: Circular measure and sectors and areas using trigonometry

4PM1/1/January/2017 — Question 1 · 5 marks

1.69 diagram 1
Figure 1 shows a sector of a circle. The circle has radius rr cm and the sector has angle θ\theta radians. The sector has an arc length of 18π18\pi cm and an area of 126π cm2126\pi\text{ cm}^2.
Find
(i) the value of rr,
(ii) the exact value of θ\theta. (5)

1.70: Areas using trigonometry

4PM1/1/January/2017 — Question 5 · 11 marks

1.70 diagram 1
Figure 2 shows the quadrilateral ABCDABCD in which AB=BCAB=BC.
DC=8 cmAC=12 cmABC=120CAD=35DC=8\text{ cm}\qquad AC=12\text{ cm}\qquad \angle ABC=120^\circ\qquad \angle CAD=35^\circ
Find
(a) the exact length, in cm, of ABAB. (2)
Given that angle ADCADC is obtuse, find
(b) the size, in degrees to 1 decimal place, of angle ADCADC, (3)
(c) the area, in cm2\text{cm}^2 to 3 significant figures, of the quadrilateral ABCDABCD. (6)

1.75: Trigonometric equations and geometry

4PM1/1/June/2017 — Question 5 · 8 marks

In triangle ABCABC, AB=10AB=10 cm, BC=7BC=7 cm and angle BAC=40BAC=40^\circ.
(a) Find, in degrees to the nearest 0.10.1^\circ, the two possible sizes of angle ACBACB. (4)
(b) Find, in cm to 3 significant figures, the difference between the two possible lengths of ACAC. (4)

1.76: Trigonometric identities, trigonometric equations and exact trigonometric values

4PM1/1/June/2017 — Question 9 · 15 marks

Using cos(A+B)=cosAcosBsinAsinB\cos(A+B)=\cos A\cos B-\sin A\sin B,
(a) show that cos2θ=12(cos2θ+1)\displaystyle\cos^2\theta=\frac12(\cos2\theta+1). (2)
f(θ)=8cos4θ+4cos2θ5f(\theta)=8\cos^4\theta+4\cos2\theta-5
(b) show that f(θ)=cos4θ+6cos2θf(\theta)=\cos4\theta+6\cos2\theta. (4)
Hence
(c) solve, for 0x<1800^\circ\le x<180^\circ, the equation
8cos4x+4cos2x6cos2x=4.58\cos^4x+4\cos^2x-6\cos2x=4.5
(4)
(d) find
(i) f(θ)dθ\displaystyle\int f(\theta)\,d\theta
(ii) the exact value of 0π/3f(θ)dθ\displaystyle\int_0^{\pi/3}f(\theta)\,d\theta. (5)

1.71: Trigonometric identities and equations

4PM1/2/January/2017 — Question 2 · 7 marks

(a) Show that the equation 6cos2αsinα=56\cos^2\alpha-\sin\alpha=5 can be written as
6sin2α+sinα1=06\sin^2\alpha+\sin\alpha-1=0
(2)
(b) Solve, to 1 decimal place where appropriate, for 0θ900\le\theta\le90,
6cos2(2θ+40)sin(2θ+40)=56\cos^2(2\theta+40)^\circ-\sin(2\theta+40)^\circ=5
(5)

1.72: Trigonometric identities and exact trigonometric values

4PM1/2/January/2017 — Question 4 · 10 marks

tan(A+B)=tanA+tanB1tanAtanB\tan(A+B)=\frac{\tan A+\tan B}{1-\tan A\tan B}
(a) (i) Write down an expression for tan(2x)\tan(2x) in terms of tanx\tan x.
(ii) Hence show that tan(3x)=3tanxtan3x13tan2x\displaystyle\tan(3x)=\frac{3\tan x-\tan^3x}{1-3\tan^2x}. (6)
Given that α\alpha is the acute angle such that cosα=13\cos\alpha=\frac13
(b) find the exact value of tanα\tan\alpha. (2)
(c) Hence use the identity in part (a) to find the exact value of tan(3α)\tan(3\alpha).
Give your answer in the form a2b\displaystyle\frac{a\sqrt2}{b} where aa and bb are integers. (2)

1.73: 3D angles in a prism

4PM1/2/January/2017 — Question 10 · 15 marks

1.73 diagram 1
Figure 1 shows a right prism ABCDEFGHIJABCDEFGHIJ. The base, DEFGDEFG, is horizontal and is a rectangle with DG=EF=10 cmDG=EF=10\text{ cm}. The midpoint of EDED is MM.
The planes ABCDEABCDE and JIHGFJIHGF are vertical.
AE=CD=GH=FJ=8 cmAB=BC=HI=IJ=6 cmBAC=30AE=CD=GH=FJ=8\text{ cm}\qquad AB=BC=HI=IJ=6\text{ cm}\qquad \angle BAC=30^\circ
(a) Show that the length of MDMD is 333\sqrt3 cm. (2)
(b) Show that the length of BMBM, the height of the prism, is 11 cm. (2)
(c) Find, in cm to 3 significant figures, the length BGBG. (3)
Find, in degrees to 1 decimal place,
(d) the size of the angle between the planes BCHIBCHI and CHFECHFE, (3)
(e) the size of the angle between the planes ABIJABIJ and BEFIBEFI. (5)

1.78: Trigonometric equations and geometry

4PM1/2/June/2017 — Question 10 · 16 marks

1.78 diagram 1
Figure 2 shows a solid cuboid ABCDEFGHABCDEFGH with EF=8EF=8 cm and EH=3EH=3 cm.
The angle between the diagonal AHAH of the cuboid and the plane ABCDABCD is 4545^\circ.
The midpoint of CHCH is NN.
Find, in cm to 3 significant figures,
(a) the length of CHCH, (4)
(b) the length of AHAH, (3)
(c) the length of FNFN. (3)
Find, in degrees to 1 decimal place, the size of
(d) the angle between the plane BCEFBCEF and the plane FGHEFGHE, (3)
(e) angle FNGFNG. (3)

1.98: Trigonometric equations

4PM1/1/January/2016 — Question 6 · 6 marks

Giving your solutions to 3 decimal places, solve the equation
(a) cosx=0.4\cos x=0.4,   π<x<π-\pi<x<\pi (2)
(b) tan ⁣(2θ+π4)=1.5\tan\!\left(2\theta+\dfrac\pi4\right)=1.5,   0<θ<π0<\theta<\pi (4)

1.99: Areas using trigonometry

4PM1/1/January/2016 — Question 7 · 8 marks

1.99 diagram 1
Figure 1 shows the triangle ABCABC with AB=4 cmAB=4\text{ cm}, BC=5 cmBC=5\text{ cm} and BCA=30\angle BCA=30^\circ. The point DD lies on ACAC such that BD=4 cmBD=4\text{ cm} and angle BDCBDC is obtuse.
Find
(a) the size of angle BDCBDC, giving your answer in degrees correct to 1 decimal place, (3)
(b) the length, in cm, of ADAD, giving your answer correct to 3 significant figures, (3)
(c) the area, in cm2\text{cm}^2, of triangle ABDABD, giving your answer correct to 3 significant figures. (2)

1.103: 3D angles in a pyramid

4PM1/1/June/2016 — Question 3 · 6 marks

A right pyramid ABCDEABCDE has a square base ABCDABCD of side 10 cm. The height of the pyramid is 8 cm.
(a) Find, to 3 significant figures, the length of AEAE. (3)
(b) Find, in degrees to the nearest degree, the size of the angle between the plane ABEABE and the base ABCDABCD. (3)

1.104: Trigonometric identities and equations

4PM1/1/June/2016 — Question 5 · 9 marks

Using the identities
sin(A+B)=sinAcosB+cosAsinB\sin(A+B)=\sin A\cos B+\cos A\sin B
tanA=sinAcosA\tan A=\dfrac{\sin A}{\cos A}
(a) show that the equation
3sin(x+α)=5sin(xα)3\sin(x+\alpha)=5\sin(x-\alpha)
can be written in the form tanx=4tanα\tan x=4\tan\alpha. (5)
(b) Hence solve, to the nearest integer, the equation
3sin(2y+30)=5sin(2y30)for 90y<1803\sin(2y+30)^\circ=5\sin(2y-30)^\circ\quad\text{for }90\le y<180
(4)

1.100: Sector geometry and area

4PM1/2/January/2016 — Question 2 · 5 marks

The sector OABOAB of a circle, centre OO, has area 48 cm248\text{ cm}^2. The length of the arc ABAB is 8 cm and the size of angle AOBAOB is θ\theta radians.
Find
(i) the radius of sector OABOAB
(ii) the value of θ\theta (5)

1.101: Trigonometric identities

4PM1/2/January/2016 — Question 6 · 6 marks

sin(A+B)=sinAcosB+cosAsinB\sin(A+B)=\sin A\cos B+\cos A\sin B
cos(A+B)=cosAcosBsinAsinB\cos(A+B)=\cos A\cos B-\sin A\sin B
sinAcosA=tanA\dfrac{\sin A}{\cos A}=\tan A
Using the above formulae, show that
(a) sin2x=2sinxcosx\sin2x=2\sin x\cos x (1)
(b) cos2x=cos2xsin2x\cos2x=\cos^2x-\sin^2x (1)
(c) sin2x1+cos2x=tanx\dfrac{\sin2x}{1+\cos2x}=\tan x (4)

1.102: 3D angles in a prism

4PM1/2/January/2016 — Question 12 · 12 marks

1.102 diagram 1
Figure 3 shows a right prism ABCDEFGHABCDEFGH. The cross section ABCDABCD of the prism is a trapezium with AB=DCAB=DC. The point MM lies on ADAD and BMBM is perpendicular to ADAD.
AB=8 cmCD=8 cmBC=8 cmAD=16 cmDE=20 cmAB=8\text{ cm}\quad CD=8\text{ cm}\quad BC=8\text{ cm}\quad AD=16\text{ cm}\quad DE=20\text{ cm}
Given that BM=pq cmBM=p\sqrt q\text{ cm} where qq is a prime number,
(a) find the value of pp and the value of qq. (3)
(b) Find the size of angle BAMBAM in degrees. (2)
Find, in degrees to the nearest 0.10.1^\circ,
(c) the size of the angle between EBEB and the plane ADEHADEH, (4)
(d) the size of the angle between the plane BCEHBCEH and the plane ADEHADEH. (3)

1.106: Trigonometric identities, trigonometric equations and exact trigonometric values

4PM1/2/June/2016 — Question 9 · 16 marks

sin(A+B)=sinAcosB+cosAsinB\sin(A+B)=\sin A\cos B+\cos A\sin B
cos(A+B)=cosAcosBsinAsinB\cos(A+B)=\cos A\cos B-\sin A\sin B
Using the above identities
(a) show that cos2θ=2cos2θ1\cos2\theta=2\cos^2\theta-1. (3)
(b) find a simplified expression for sin2θ\sin2\theta in terms of sinθ\sin\theta and cosθ\cos\theta. (1)
(c) show that cos3θ=4cos3θ3cosθ\cos3\theta=4\cos^3\theta-3\cos\theta. (4)
Hence, or otherwise,
(d) solve, for 0θ<π0\le\theta<\pi, giving your answers in terms of π\pi, the equation
6cosθ8cos3θ+1=06\cos\theta-8\cos^3\theta+1=0
(4)
(e) find
(i) (8cos3θ+4sinθ)dθ\displaystyle\int(8\cos^3\theta+4\sin\theta)\,d\theta
(ii) the exact value of 0π/3(8cos3θ+4sinθ)dθ\displaystyle\int_0^{\pi/3}(8\cos^3\theta+4\sin\theta)\,d\theta (4)

1.89: Trigonometric identities and equations

4PM1/1/January/2015 — Question 8 · 12 marks

tanθ=sinθcosθ\tan\theta=\dfrac{\sin\theta}{\cos\theta}
(a) Show that 1+tan2θ=1cos2θ1+\tan^2\theta=\dfrac1{\cos^2\theta}. (3)
(b) Show that
1+sinθcosθ+sin2θcos2θ=1+tanθ+2tan2θ\dfrac{1+\sin\theta\cos\theta+\sin^2\theta}{\cos^2\theta}=1+\tan\theta+2\tan^2\theta
(3)
(c) Solve, for 0θ1800^\circ\le\theta\le180^\circ,
1+sinθcosθ+sin2θ=4cos2θ1+\sin\theta\cos\theta+\sin^2\theta=4\cos^2\theta
giving your answers in degrees to 1 decimal place where appropriate. (6)

1.94: Sector geometry and area

4PM1/1/June/2015 — Question 6 · 10 marks

1.94 diagram 1
Figure 1 shows ABC\triangle ABC with AB=22AB=22 cm, AC=14AC=14 cm and BC=20BC=20 cm.
(a) Find, to 3 decimal places, the size of each of the three angles of ABC\triangle ABC. (5)
The bisector of angle BACBAC meets BCBC at PP.
(b) Find, in cm to 3 significant figures, the length of APAP. (3)
(c) Find, to the nearest cm2\text{cm}^2, the area of ABC\triangle ABC. (2)

1.95: Trigonometric identities and equations

4PM1/1/June/2015 — Question 8 · 17 marks

Using the identities
cos(A+B)=cosAcosBsinAsinB\cos(A+B)=\cos A\cos B-\sin A\sin B
sin(A+B)=sinAcosB+cosAsinB\sin(A+B)=\sin A\cos B+\cos A\sin B
(a) (i) show that cos2A=12sin2A\cos2A=1-2\sin^2A, (3)
(ii) express sin2A\sin2A in terms of sinA\sin A and cosA\cos A, simplifying your answer. (1)
(b) Hence show that sin3A=3sinA4sin3A\sin3A=3\sin A-4\sin^3A. (4)
(c) Solve, for 90A90-90^\circ\le A\le90^\circ, the equation 8sin3A6sinA=18\sin^3A-6\sin A=1. (4)
(d) (i) Find sin3θdθ\displaystyle\int\sin^3\theta\,d\theta.
(ii) Evaluate 0π/4sin3θdθ\displaystyle\int_0^{\pi/4}\sin^3\theta\,d\theta, giving your answer in the form ab2c\dfrac{a-b\sqrt2}{c}, where a,b,ca,b,c are integers. (5)

1.90: Areas using trigonometry

4PM1/2/January/2015 — Question 1 · 7 marks

1.90 diagram 1
In triangle ABCABC, AB=xAB=x cm, AC=2xAC=2x cm and ABC=100\angle ABC=100^\circ, as shown in Figure 1.
(a) Find, in degrees to the nearest 0.10.1^\circ, the size of BAC\angle BAC. (4)
Given that the area of triangle ABCABC is 16 cm216\text{ cm}^2,
(b) find, to 3 significant figures, the value of xx. (3)

1.91: Trigonometric identities and exact trigonometric values

4PM1/2/January/2015 — Question 4 · 7 marks

sin(A+B)=sinAcosB+cosAsinB\sin(A+B)=\sin A\cos B+\cos A\sin B
cos(A+B)=cosAcosBsinAsinB\cos(A+B)=\cos A\cos B-\sin A\sin B
(a) Write down the exact value of sin45\sin45^\circ. (1)
Given that sinθ=522\sin\theta=\dfrac{\sqrt5}{2\sqrt2} and cosθ=322\cos\theta=\dfrac{\sqrt3}{2\sqrt2},
(b) show that sin(45+θ)=3+54\sin(45^\circ+\theta)=\dfrac{\sqrt3+\sqrt5}{4}. (2)
(c) Find the exact value of cos(45+θ)\cos(45^\circ+\theta). (2)
(d) Show that sin(45+θ)×cos(45+θ)=18\sin(45^\circ+\theta)\times\cos(45^\circ+\theta)=-\dfrac18. (2)

1.92: Estimate roots using a graph

4PM1/2/January/2015 — Question 5 · 8 marks

1.92 diagram 1
The grid opposite shows the graph of y=3xsinxy=3x\sin x for 1x3-1\le x\le3, where xx is measured in radians.
(a) Use the graph to estimate, to 1 decimal place, the roots of the equation xsinx=1x\sin x=1 in the interval 1x3-1\le x\le3. (3)
(b) By drawing a suitable straight line on the grid, obtain estimates, to 1 decimal place, of the roots of the equation 2xsinxx=12x\sin x-x=1 in the interval 1x3-1\le x\le3. (5)

1.93: $AB=BC=CA=10$ cm and $DA=DB=DC=13$ cm

4PM1/2/January/2015 — Question 9 · 15 marks

1.93 diagram 1
Figure 2 shows a triangular pyramid ABCDABCD.
AB=BC=CA=10AB=BC=CA=10 cm and DA=DB=DC=13DA=DB=DC=13 cm. The point EE is the midpoint of ACAC.
(a) Find the exact length of
(i) DEDE
(ii) BEBE (4)
(b) Find, in degrees to 1 decimal place, the size of the angle between the line BDBD and the line DEDE. (3)
(c) Find, in degrees to 1 decimal place, the size of the angle between the line BDBD and the plane ABCABC. (3)
(d) Find, in degrees to 1 decimal place, the size of the angle between the plane ADCADC and the plane ABCABC. (2)
(e) Find, to 3 significant figures, the volume of the pyramid ABCDABCD. (3)

1.97: 3D angles in a pyramid

4PM1/2/June/2015 — Question 7 · 12 marks

1.97 diagram 1
Figure 2 shows a solid VABCDEFGHVABCDEFGH which is formed by joining a cuboid ABCDEFGHABCDEFGH to a right pyramid VABCDVABCD. The height of the cuboid and the height of the pyramid are both hh cm and FG=8FG=8 cm and GH=6GH=6 cm. The total volume of the solid is 256 cm3256\text{ cm}^3.
(a) Show that h=4h=4. (2)
(b) Find, in cm to 3 significant figures, the length of VFVF. (3)
Find, to the nearest 0.10.1^\circ,
(c) the angle between VAVA and the plane ABCDABCD, (3)
(d) the acute angle between the plane VABVAB and the plane ABHEABHE. (4)