OCR MEI C1 — Question 3 3 marks

Exam BoardOCR MEI
ModuleC1 (Core Mathematics 1)
Marks3
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicBinomial Theorem (positive integer n)
TypeSingle binomial expansion
DifficultyModerate -0.3 This is a straightforward binomial expansion question requiring students to identify which term has x^0. While it involves negative powers and requires careful algebraic manipulation of indices, it's a standard textbook exercise with a clear method: expand using the binomial theorem and find where the powers of x cancel. Slightly easier than average due to the small power (n=4) and single-step nature once the expansion is written.
Spec1.04a Binomial expansion: (a+b)^n for positive integer n

3 Find the term independent of \(x\) in the expansion of \(\left( x - \frac { 2 } { x } \right) ^ { 4 }\).

Question 3:
AnswerMarks Guidance
Term independent of \(x\) is \(6x^2 \cdot \left(-\frac{2}{x}\right)^2\) (Middle term)M1 Attempt at correct term
Coefficient \(= 6\)A1 Coefficient \(= 6\)
Coefficient \(= 24\)A1 cao. Total: 3
# Question 3:
Term independent of $x$ is $6x^2 \cdot \left(-\frac{2}{x}\right)^2$ (Middle term) | M1 | Attempt at correct term
Coefficient $= 6$ | A1 | Coefficient $= 6$
Coefficient $= 24$ | A1 | cao. **Total: 3**

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3 Find the term independent of $x$ in the expansion of $\left( x - \frac { 2 } { x } \right) ^ { 4 }$.

\hfill \mbox{\textit{OCR MEI C1  Q3 [3]}}