Mathematics 9709 · AS & A Level · Functions

Functions — practice question

The function $f$ is defined by $f(x) = a^2x^2 - ax + 3b$ for $x \leq \frac{1}{2a}$, with $a$ and $b$ as constants.
(i)[5]

In the case where $f(-2) = 4a^2 - b + 8$ and $f(-3) = 7a^2 - b + 14$, determine the possible values of $a$ and $b$.

(ii)[5]

When $a = 1$ and $b = -1$, determine an expression for $f^{-1}(x)$ and state the domain of $f^{-1}$.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: Substitutes the given values into $2a+4b=8$

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