| Exam Board | OCR MEI |
|---|---|
| Module | C4 (Core Mathematics 4) |
| Year | 2012 |
| Session | January |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Generalised Binomial Theorem |
| Type | Finding unknown power and constant |
| Difficulty | Standard +0.3 This is a straightforward binomial expansion problem requiring students to equate coefficients to find two unknowns, then apply the standard validity condition |qx| < 1. It's slightly above average difficulty due to the negative coefficient requiring careful algebraic manipulation, but follows a well-practiced procedure with no novel insight needed. |
| Spec | 1.04c Extend binomial expansion: rational n, |x|<11.04d Binomial expansion validity: convergence conditions |
Given the binomial expansion $(1 + qx)^p = 1 - x + 2x^2 + \ldots$, find the values of $p$ and $q$. Hence state the set of values of $x$ for which the expansion is valid. [6]
\hfill \mbox{\textit{OCR MEI C4 2012 Q6 [6]}}