AQA C3 2012 June — Question 5

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

5 The functions f and g are defined with their respective domains by $$\begin{array} { l l } \mathrm { f } ( x ) = \sqrt { 2 x - 5 } , & \text { for } x \geqslant 2.5
\mathrm {~g} ( x ) = \frac { 10 } { x } , & \text { for real values of } x , \quad x \neq 0 \end{array}$$
  1. State the range of f .
    1. Find \(\mathrm { fg } ( x )\).
    2. Solve the equation \(\operatorname { fg } ( x ) = 5\).
  2. The inverse of f is \(\mathrm { f } ^ { - 1 }\).
    1. Find \(\mathrm { f } ^ { - 1 } ( x )\).
    2. Solve the equation \(\mathrm { f } ^ { - 1 } ( x ) = 7\).