AQA C3 2012 January — Question 2

Exam BoardAQA
ModuleC3 (Core Mathematics 3)
Year2012
SessionJanuary
TopicComposite & Inverse Functions

2 The curve with equation \(y = \frac { 63 } { 4 x - 1 }\) is sketched below for \(1 \leqslant x \leqslant 16\).
\includegraphics[max width=\textwidth, alt={}, center]{7aa76d26-e3c4-4374-ae4f-8bb61e61b135-2_568_698_1308_669} The function f is defined by \(\mathrm { f } ( x ) = \frac { 63 } { 4 x - 1 }\) for \(1 \leqslant x \leqslant 16\).
  1. Find the range of f .
  2. The inverse of f is \(\mathrm { f } ^ { - 1 }\).
    1. Find \(\mathrm { f } ^ { - 1 } ( x )\).
    2. Solve the equation \(\mathrm { f } ^ { - 1 } ( x ) = 1\).
  3. The function g is defined by \(\mathrm { g } ( x ) = x ^ { 2 }\) for \(- 4 \leqslant x \leqslant - 1\).
    1. Write down an expression for \(\mathrm { fg } ( x )\).
    2. Solve the equation \(\operatorname { fg } ( x ) = 1\).