AQA C2 2006 June — Question 4 8 marks

Exam BoardAQA
ModuleC2 (Core Mathematics 2)
Year2006
SessionJune
Marks8
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Mark schemeDownload PDF ↗
TopicBinomial Theorem (positive integer n)
TypeStandard product of two binomials
DifficultyModerate -0.3 This is a straightforward binomial expansion question requiring routine application of the binomial theorem. Part (a) involves simple expansion of a small power with pattern matching, part (b) is direct application of the binomial coefficient formula, and part (c) requires multiplying terms from two expansions—a standard technique. While multi-part, each step is procedural with no novel insight required, making it slightly easier than average.
Spec1.04a Binomial expansion: (a+b)^n for positive integer n

4
  1. The expression \(( 1 - 2 x ) ^ { 4 }\) can be written in the form $$1 + p x + q x ^ { 2 } - 32 x ^ { 3 } + 16 x ^ { 4 }$$ By using the binomial expansion, or otherwise, find the values of the integers \(p\) and \(q\).
  2. Find the coefficient of \(x\) in the expansion of \(( 2 + x ) ^ { 9 }\).
  3. Find the coefficient of \(x\) in the expansion of \(( 1 - 2 x ) ^ { 4 } ( 2 + x ) ^ { 9 }\).

4
\begin{enumerate}[label=(\alph*)]
\item The expression $( 1 - 2 x ) ^ { 4 }$ can be written in the form

$$1 + p x + q x ^ { 2 } - 32 x ^ { 3 } + 16 x ^ { 4 }$$

By using the binomial expansion, or otherwise, find the values of the integers $p$ and $q$.
\item Find the coefficient of $x$ in the expansion of $( 2 + x ) ^ { 9 }$.
\item Find the coefficient of $x$ in the expansion of $( 1 - 2 x ) ^ { 4 } ( 2 + x ) ^ { 9 }$.
\end{enumerate}

\hfill \mbox{\textit{AQA C2 2006 Q4 [8]}}