Edexcel C3 2015 June — Question 2

Exam BoardEdexcel
ModuleC3 (Core Mathematics 3)
Year2015
SessionJune
TopicModulus function

2. Given that $$\mathrm { f } ( x ) = 2 \mathrm { e } ^ { x } - 5 , \quad x \in \mathbb { R }$$
  1. sketch, on separate diagrams, the curve with equation
    1. \(y = \mathrm { f } ( x )\)
    2. \(y = | \mathrm { f } ( x ) |\) On each diagram, show the coordinates of each point at which the curve meets or cuts the axes. On each diagram state the equation of the asymptote.
  2. Deduce the set of values of \(x\) for which \(\mathrm { f } ( x ) = | \mathrm { f } ( x ) |\)
  3. Find the exact solutions of the equation \(| \mathrm { f } ( x ) | = 2\)