| Exam Board | Edexcel |
|---|---|
| Module | C4 (Core Mathematics 4) |
| Marks | 5 |
| Paper | Download PDF ↗ |
| Topic | Generalised Binomial Theorem |
| Type | Form (a+bx)^n requiring factorisation |
| Difficulty | Moderate -0.3 This is a straightforward application of the binomial expansion for fractional powers. Students must rewrite as 2(1-9x/4)^(1/2), apply the standard formula with n=1/2, and simplify coefficients—routine technique with no problem-solving required, though the algebraic manipulation makes it slightly less trivial than pure recall. |
| Spec | 1.04c Extend binomial expansion: rational n, |x|<1 |
Use the binomial theorem to expand
$$\sqrt{(4-9x)}, \quad |x| < \frac{4}{9},$$
in ascending powers of $x$, up to and including the term in $x^3$, simplifying each term.
[5]
\hfill \mbox{\textit{Edexcel C4 Q1 [5]}}