Edexcel P2 2021 October — Question 1

Exam BoardEdexcel
ModuleP2 (Pure Mathematics 2)
Year2021
SessionOctober
TopicBinomial Theorem (positive integer n)
TypeFirst few terms given find parameters

  1. The first three terms, in ascending powers of \(x\), of the binomial expansion of \(( 1 + k x ) ^ { 16 }\) are
$$1 , - 4 x \text { and } p x ^ { 2 }$$ where \(k\) and \(p\) are constants.
  1. Find, in simplest form,
    1. the value of \(k\)
    2. the value of \(p\) $$g ( x ) = \left( 2 + \frac { 16 } { x } \right) ( 1 + k x ) ^ { 16 }$$ Using the value of \(k\) found in part (a),
  2. find the term in \(x ^ { 2 }\) in the expansion of \(\mathrm { g } ( x )\). $$\begin{aligned} u _ { 1 } & = 6
    u _ { n + 1 } & = k u _ { n } + 3 \end{aligned}$$ where \(k\) is a positive constant.
  3. Find, in terms of \(k\), an expression for \(u _ { 3 }\) Given that \(\sum _ { n = 1 } ^ { 3 } u _ { n } = 117\)
  4. find the value of \(k\).