OCR C2 2010 June — Question 3 7 marks

Exam BoardOCR
ModuleC2 (Core Mathematics 2)
Year2010
SessionJune
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicBinomial Theorem (positive integer n)
TypeBinomial times quadratic coefficient
DifficultyStandard +0.3 Part (i) is straightforward application of binomial theorem requiring calculation of four terms. Part (ii) requires multiplying the expansion by a quadratic and collecting x³ terms—a standard extension that tests understanding but involves routine algebraic manipulation with no novel insight required.
Spec1.04a Binomial expansion: (a+b)^n for positive integer n

3
  1. Find and simplify the first four terms in the binomial expansion of \(\left( 1 + \frac { 1 } { 2 } x \right) ^ { 10 }\) in ascending powers of \(x\).
  2. Hence find the coefficient of \(x ^ { 3 }\) in the expansion of \(\left( 3 + 4 x + 2 x ^ { 2 } \right) \left( 1 + \frac { 1 } { 2 } x \right) ^ { 10 }\).

3 (i) Find and simplify the first four terms in the binomial expansion of $\left( 1 + \frac { 1 } { 2 } x \right) ^ { 10 }$ in ascending powers of $x$.\\
(ii) Hence find the coefficient of $x ^ { 3 }$ in the expansion of $\left( 3 + 4 x + 2 x ^ { 2 } \right) \left( 1 + \frac { 1 } { 2 } x \right) ^ { 10 }$.

\hfill \mbox{\textit{OCR C2 2010 Q3 [7]}}