Edexcel C12 2017 January — Question 10

Exam BoardEdexcel
ModuleC12 (Core Mathematics 1 & 2)
Year2017
SessionJanuary
TopicBinomial Theorem (positive integer n)
TypeFirst few terms given find parameters

10. The first 3 terms, in ascending powers of \(x\), in the binomial expansion of \(( 1 + a x ) ^ { 20 }\) are given by $$1 + 4 x + p x ^ { 2 }$$ where \(a\) and \(p\) are constants.
  1. Find the value of \(a\).
  2. Find the value of \(p\). One of the terms in the binomial expansion of \(( 1 + a x ) ^ { 20 }\) is \(q x ^ { 4 }\), where \(q\) is a constant.
  3. Find the value of \(q\).