| Exam Board | OCR MEI |
|---|---|
| Module | C4 (Core Mathematics 4) |
| Year | 2011 |
| Session | January |
| Marks | 7 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Generalised Binomial Theorem |
| Type | Series expansion of rational function |
| Difficulty | Moderate -0.3 This is a straightforward application of the binomial expansion formula requiring students to rewrite the expression in the form (1+bx)^n, expand using the standard formula, and state the validity condition |bx|<1. It's slightly easier than average because it's a routine textbook exercise with clear steps, though it does require careful algebraic manipulation and understanding of convergence conditions. |
| Spec | 1.04c Extend binomial expansion: rational n, |x|<11.04d Binomial expansion validity: convergence conditions |
3 Find the first three terms in the binomial expansion of $\frac { 1 } { ( 3 - 2 x ) ^ { 3 } }$ in ascending powers of $x$. State the set of values of $x$ for which the expansion is valid.
\hfill \mbox{\textit{OCR MEI C4 2011 Q3 [7]}}