CAIE P1 2020 March — Question 9

Exam BoardCAIE
ModuleP1 (Pure Mathematics 1)
Year2020
SessionMarch
TopicComposite & Inverse Functions

9
  1. Express \(2 x ^ { 2 } + 12 x + 11\) in the form \(2 ( x + a ) ^ { 2 } + b\), where \(a\) and \(b\) are constants.
    The function f is defined by \(\mathrm { f } ( x ) = 2 x ^ { 2 } + 12 x + 11\) for \(x \leqslant - 4\).
  2. Find an expression for \(\mathrm { f } ^ { - 1 } ( x )\) and state the domain of \(\mathrm { f } ^ { - 1 }\).
    The function g is defined by \(\mathrm { g } ( x ) = 2 x - 3\) for \(x \leqslant k\).
  3. For the case where \(k = - 1\), solve the equation \(\operatorname { fg } ( x ) = 193\).
  4. State the largest value of \(k\) possible for the composition fg to be defined.