Edexcel C3 2010 January — Question 9

Exam BoardEdexcel
ModuleC3 (Core Mathematics 3)
Year2010
SessionJanuary
TopicExponential Equations & Modelling

9. (i) Find the exact solutions to the equations
  1. \(\ln ( 3 x - 7 ) = 5\)
  2. \(3 ^ { x } \mathrm { e } ^ { 7 x + 2 } = 15\)
    (ii) The functions f and g are defined by $$\begin{array} { l l } \mathrm { f } ( x ) = \mathrm { e } ^ { 2 x } + 3 , & x \in \mathbb { R }
    \mathrm {~g} ( x ) = \ln ( x - 1 ) , & x \in \mathbb { R } , x > 1 \end{array}$$
  3. Find \(\mathrm { f } ^ { - 1 }\) and state its domain.
  4. Find fg and state its range.