OCR C2 — Question 6 9 marks

Exam BoardOCR
ModuleC2 (Core Mathematics 2)
Marks9
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicBinomial Theorem (positive integer n)
TypeExpress result in specific form
DifficultyModerate -0.5 Part (a) is straightforward binomial expansion with n=4. Part (b)(i) is direct substitution. Part (b)(ii) requires recognizing that (1-√2)^8 = [(1-√2)^4]^2 and using conjugate properties, which adds modest problem-solving but remains a standard C2 exercise with clear structure and routine techniques.
Spec1.02b Surds: manipulation and rationalising denominators1.04a Binomial expansion: (a+b)^n for positive integer n

  1. (a) Expand \(( 1 + x ) ^ { 4 }\) in ascending powers of \(x\).
    (b) Using your expansion, express each of the following in the form \(a + b \sqrt { 2 }\), where \(a\) and \(b\) are integers.
    1. \(( 1 + \sqrt { 2 } ) ^ { 4 }\)
    2. \(( 1 - \sqrt { 2 } ) ^ { 8 }\)
    3. The second and fifth terms of an arithmetic sequence are 26 and 41 repectively.

\begin{enumerate}
  \item (a) Expand $( 1 + x ) ^ { 4 }$ in ascending powers of $x$.\\
(b) Using your expansion, express each of the following in the form $a + b \sqrt { 2 }$, where $a$ and $b$ are integers.\\
(i) $( 1 + \sqrt { 2 } ) ^ { 4 }$\\
(ii) $( 1 - \sqrt { 2 } ) ^ { 8 }$
  \item The second and fifth terms of an arithmetic sequence are 26 and 41 repectively.\\
\end{enumerate}

\hfill \mbox{\textit{OCR C2  Q6 [9]}}