Target Mathematics

2.5: Cosecant–cotangent identity and tan equation

0606/21/M/J/19 — Question 11 · 9 marks

(a)(i)
Show that cscθcotθsinθ=11+cosθ\dfrac{\csc \theta - \cot \theta}{\sin \theta} = \dfrac{1}{1 + \cos \theta}.
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(a)(ii)
Hence solve cscθcotθsinθ=52\dfrac{\csc \theta - \cot \theta}{\sin \theta} = \tfrac{5}{2} for 180°<θ<360°180^{\degree} < \theta < 360^{\degree}.
[2]
(b)
Solve tan(3ϕ4)=12\tan(3\phi - 4) = -\tfrac{1}{2} for 0ϕπ20 \le \phi \le \tfrac{\pi}{2} radians.
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