Edexcel C34 Specimen — Question 5

Exam BoardEdexcel
ModuleC34 (Core Mathematics 3 & 4)
SessionSpecimen
TopicComposite & Inverse Functions

  1. The functions \(f\) and \(g\) are defined by
$$\begin{array} { l l } \mathrm { f } : x \mapsto \mathrm { e } ^ { - x } + 2 , & x \in \mathbb { R }
\mathrm {~g} : x \mapsto 2 \ln x , & x > 0 \end{array}$$
  1. Find \(\mathrm { fg } ( x )\), giving your answer in its simplest form.
  2. Find the exact value of \(x\) for which \(\mathrm { f } ( 2 x + 3 ) = 6\)
  3. Find \(\mathrm { f } ^ { - 1 }\), stating its domain.
  4. 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.