CAIE P1 2022 March — Question 11

Exam BoardCAIE
ModuleP1 (Pure Mathematics 1)
Year2022
SessionMarch
TopicProduct & Quotient Rules

11 It is given that a curve has equation \(y = k ( 3 x - k ) ^ { - 1 } + 3 x\), where \(k\) is a constant.
  1. Find, in terms of \(k\), the values of \(x\) at which there is a stationary point.
    The function f has a stationary value at \(x = a\) and is defined by $$f ( x ) = 4 ( 3 x - 4 ) ^ { - 1 } + 3 x \quad \text { for } x \geqslant \frac { 3 } { 2 }$$
  2. Find the value of \(a\) and determine the nature of the stationary value.
  3. The function g is defined by \(\mathrm { g } ( x ) = - ( 3 x + 1 ) ^ { - 1 } + 3 x\) for \(x \geqslant 0\). Determine, making your reasoning clear, whether \(g\) is an increasing function, a decreasing function or neither.
    If you use the following lined page to complete the answer(s) to any question(s), the question number(s) must be clearly shown.