Past-paper practice
The Quadratic Function: Topic Questions
46 questions with mark schemes.
Given that can be written in the form where , and are rational numbers,
(a) find the value of , the value of and the value of
(3)
(b) Hence, or otherwise, write down
(i) the minimum value of
(ii) the value of at which this minimum value occurs.
(2)
1.2: Relationships between roots
(a) Show that
(1)
The equation has roots and and where is a constant
Given that
(b) show that
(4)
Given that and without solving the equation
(c) (i) show that
(3)
(ii) hence find the exact value of
(2)
1.3: Relationships between roots
(a) Show that
(2)
The quadratic equation has roots and
Without solving the equation
(b) form a quadratic equation, with integer coefficients, which has roots and
(6)
1.4: Relationships between roots
The curve has equation
The line with equation is a tangent to
The line is perpendicular to and is also the tangent to at the point where
(a) Find the value of
(5)
(b) Show that
(2)
The quadratic equation has roots and
Without solving the equation and using your results from part (b)
(c) form a quadratic equation with integer coefficients, that has roots
(8)
1.5: Relationships between roots and quadratic graphs
Given that can be expressed in the form where , and are positive constants
(a) find the value of , the value of and the value of
(4)
(b) Hence write down the maximum value of
(1)
The equation has roots and
Without solving the equation
(c) form a quadratic equation, with integer coefficients, that has roots and
(6)
(d) Show that
(1)
where and are constants
The equation has roots and where and are the roots of the equation
(e) Using your answer to part (d), find in simplified exact form, the value of and the value of
(6)
1.6: Quadratic graphs
Given that can be written in the form , where , and are integers,
(a) find the value of , the value of and the value of
(3)
(b) Hence, or otherwise, find
(i) the value of for which is a maximum
(ii) the maximum value of
(2)
1.7: Relationships between roots
The quadratic equation has roots and such that
Given that
(a) show that
(8)
(b) Hence form a quadratic equation that has roots
(4)
1.8: Relationships between roots
The quadratic equation has roots and
Without solving the equation,
form a quadratic equation with integer coefficients, that has roots and
(8)
1.9: Values of a parameter for real roots
The quadratic equation
has equal roots.
Find the two possible values of
(4)
1.10: Quadratic graphs
(a) Express in the form where and are rational numbers to be found.
(3)
(b) Find
(i) the minimum value of
(ii) the value of at which this minimum occurs.
(2)
(c) Hence, or otherwise, write down
(i) the minimum value of
(ii) the value of at which this minimum occurs.
(2)
1.11: Values of a parameter for real roots
The equation where is a constant, has real unequal roots.
Find the set of values of giving your answer in an exact simplified form.
(5)
1.12: Relationships between roots
The roots of a quadratic equation are and where
(a) Show that
(3)
(b) Form a quadratic equation with integer coefficients, that has roots
(7)
1.14: Relationships between roots
The roots of a quadratic equation are and where
Given that and
(a) show that
(4)
(2)
(b) Without solving
(2)
(2)
Given that where and are positive integers,
(c) find the value of and the value of
(2)
1.15: Discriminant and roots
Show that for all values of , the equation has distinct real roots.
(4)
1.16: Relationships between roots
The equation has roots and
(a) find the value of
(5)
Without solving the equation
(b) form a quadratic equation, with integer coefficients, that has roots
(5)
1.17: Areas in a flag design

Figure 1 shows the design for a flag consisting of a white cross on a grey background. and are squares with sides of length . and are rectangles with sides of length and . The width of the cross is .
The total area of the flag is .
(a) Write down an expression, in terms of and , for .
(1)
Given that the area of the cross is ,
(b) show that
(3)
The total area of the flag is to be and the area of the cross is to be .
(c) Find the value of and the value of .
(5)
1.19: Values of a parameter for real roots
Find the set of values of for which the equation
has real roots.
(4)
1.20: Relations between the roots of a quadratic
The roots of the quadratic equation
are and .
(a) Write down an expression in terms of for
(i) ,
(ii) .
(2)
(b) Show that
(4)
Given that ,
(c) find the possible values of .
(3)
1.21: Values of a parameter for real roots
The quadratic equation
has real roots. Find the set of possible values of .
(6)
1.22: Transform the roots of a quadratic
(a) Show that
(3)
The quadratic equation
where is a positive constant, has roots and , where .
(b) Show that
(3)
(c) Hence form a quadratic equation with roots and . Give your equation in the form
where and should be given in terms of .
(4)
1.23: Complete the square and find a maximum
Given that can be expressed in the form
where , and are constants,
(a) find the value of , the value of and the value of .
(4)
(b) Hence write down
(i) the maximum value of ,
(ii) the value of for which this maximum occurs.
(2)
1.24: Complete the square and find an enclosed area
Given that can be written in the form , where and are constants,
(a) find the value of and the value of .
(2)
(b) Hence, or otherwise, find
(i) the minimum value of ,
(ii) the value of for which this minimum occurs.
(2)
The curve has equation . The line has equation .
(c) Use algebra to find the coordinates of the points of intersection of and .
(4)
(d) Use algebraic integration to find the exact area of the finite region bounded by and .
(5)
1.25: A quadratic curve and a straight line
(a) Express
in the form , where and are constants whose values are to be found.
(2)
(b) Use algebra to solve the simultaneous equations
(5)
Using the same axes and the results of parts (a) and (b),
(c) sketch the curve and the line , showing clearly the coordinates of the turning point and the points of intersection.
(4)
1.26: Transform the roots of a quadratic
The roots of the quadratic equation are and .
The roots of the quadratic equation are
Without solving the equation ,
(a) show that
(3)
(b) find the value of .
(4)
1.27: Equations whose roots are transformations of quadratic roots
The equation has roots and .
Without solving the equation ,
(a) form an equation, with integer coefficients, that has roots
(6)
where and are constants.
Given that the equation has roots and ,
(b) find the value of and the value of .
(5)
1.29: Real roots and transformed roots
(a) Find the set of values of for which the equation
has real roots.
(4)
Given that the roots of the equation are and ,
(b) form a quadratic equation with roots
Give each coefficient in terms of .
(8)
1.30: Completed square form of a quadratic
Given that can be written in the form , where , and are constants, find
(a) the value of , the value of and the value of .
(3)
(b) Hence write down
(i) the minimum value of ,
(ii) the value of at which this minimum occurs.
(2)
1.33: Complete the square and unequal roots
Given that can be written in the form ,
(a) find the value of , the value of and the value of .
(3)
(b) Write down
(i) the minimum value of ,
(ii) the value of at which this minimum occurs.
(2)
The equation has unequal real roots.
(c) Find the set of possible values of .
(5)
1.31: Symmetric functions of roots of a quadratic
The roots of the equation are and .
(a) Without solving the equation, find
(i) the value of
(ii) the value of
(5)
Given that and without solving the equation
(b) show that .
(2)
(c) Factorise completely.
(3)
(d) Hence find the exact value of .
(2)
Given that where and are positive constants
(e) find the value of and the value of .
(3)
1.34: Symmetric functions of quadratic roots
The roots of the equation are and , where .
Without solving the equation,
(a) find the value of ,
(3)
(b) show that ,
(2)
(c) form a quadratic equation, with integer coefficients, that has roots and .
(6)
1.13: Value of q and range of p for one real root
Given that
(a) find the value of .
(2)
(b) Find the range of values of for which the cubic equation has only one real root.
(5)
1.32: Quadratic equation with roots in terms of k
The quadratic equation where , has roots and .
Given that and that where
(a) (i) write down the value of ,
(ii) find an expression, in terms of , for .
(5)
Given also that
(b) find the value of .
(2)
(c) Hence form an equation, with integer coefficients, which has roots
(5)
1.39: Quadratic graphs
Given that can be written in the form , where , and are rational numbers,
(a) find the value of , the value of and the value of . (3)
(b) Hence, or otherwise, find
(i) the maximum value of ,
(ii) the value of for which this maximum occurs. (2)
(c) Write down
(i) the maximum value of ,
(ii) the exact value of for which this maximum occurs. (3)
1.40: Relationships between roots
It is given that and are such that and .
(a) Form a quadratic equation with integer coefficients that has roots and . (2)
Without solving the equation found in part (a)
(b) find the value of
(i)
(ii) (5)
(c) Hence form a quadratic equation with integer coefficients that has roots
(6)
1.42: Relationships between roots
The equation has roots and .
Without solving this equation, form a quadratic equation with integer coefficients that has roots
(7)
1.41: Here is a quadratic equation where is a constant.
Here is a quadratic equation
where is a constant.
(a) Find the set of values of for which the equation has two real distinct roots. (5)
(b) List all the possible integer values of for which the equation has no real roots. (1)
1.35: Relationships between roots
The equation has roots and .
(a) Without solving the equation, write down
(i) the value of
(ii) the value of (2)
(b) Without solving the equation, show that . (3)
(c) Form a quadratic equation, with integer coefficients, that has roots and . (5)
1.36: Quadratic equations and functions
Solve the equations
(5)
1.37: Discriminant and roots
(a) Find the set of possible values of for which the equation has no real roots. (3)
(b) Find the integer values of for which the equation has real roots. (3)
1.38: Relationships between roots
, .
The roots of the equation are and .
(a) Find, in terms of where necessary,
(i) (ii) (4)
Given that ,
(b) find the possible values of . (2)
Using the positive value of found in part (b) and without solving the equation ,
(c) form a quadratic equation with roots and . (5)
1.49: Values of a parameter for real roots
The roots of the equation are and .
(a) Without solving the equation , form an equation, with integer coefficients, which has
(i) roots and (6)
(ii) roots and (5)
(b) Express in the form , stating the values of the constants and . (3)
(c) Hence, or otherwise, show that the equation has no real roots. (2)
1.48: Relationships between roots
Given that and
(a) show that . (2)
(b) Hence form a quadratic equation, with integer coefficients, which has roots and . (2)
(c) Form a quadratic equation, with integer coefficients, which has roots and . (5)
1.45: Quadratic graphs
Given that , for all values of ,
(a) find the value of , the value of and the value of . (3)
(b) Hence, or otherwise, find
(i) the minimum value of ,
(ii) the value of for which this minimum occurs. (2)
1.46: Relationships between roots
(a) Show that . (1)
The roots of the equation are and , where . Without solving the equation,
(b) find the value of . (4)
(c) show that . (2)
(d) Hence find the exact value of . (2)
1.43: Values of a parameter for real roots
The equation , where is a constant, has two equal roots.
(a) Find the value of . (2)
(b) Solve the equation. (2)
1.44: Relationships between roots
The equation , where is a constant, has roots and .
(a) Find the value of
(i)
(ii) (4)
(b) Find, in terms of ,
(i)
(ii) (4)
Given that
(c) find the value of . (1)
(d) Using the value of found in part (c), find a quadratic equation, with integer coefficients, which has roots and . (2)
