Mathematics 9709 · AS & A Level · Functions

Functions — practice question

The function $f$ is given by $f(x) = x^2 + 4ax + a$ for every $x \in \mathbb{R}$, with $a$ a constant. The function $g$ is defined so that $g^{-1}(x) = \sqrt[3]{2x - 4}$ for every $x \in \mathbb{R}$.
(a)[4]

If the range of $f$ is $f(x) \ge -33$, determine the possible values of $a$.

(b)[6]

If instead $fgg(0) = 96$, determine the value of $a$.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: Completed-square form: $f(x)=(x+2a)^2-4a^2+a$

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