Edexcel C3 2012 June — Question 6

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

6. The functions \(f\) and \(g\) are defined by $$\begin{aligned} & \mathrm { f } : x \mapsto \mathrm { e } ^ { x } + 2 , \quad x \in \mathbb { R }
& \mathrm {~g} : x \mapsto \ln x , \quad x > 0 \end{aligned}$$
  1. State the range of f.
  2. Find \(\mathrm { fg } ( x )\), giving your answer in its simplest form.
  3. Find the exact value of \(x\) for which \(\mathrm { f } ( 2 x + 3 ) = 6\)
  4. Find \(\mathrm { f } ^ { - 1 }\), the inverse function of f , stating its domain.
  5. On the same axes sketch the curves with equation \(y = \mathrm { f } ( x )\) and \(y = \mathrm { f } ^ { - 1 } ( x )\), giving the coordinates of all the points where the curves cross the axes.