| Exam Board | Edexcel |
|---|---|
| Module | C2 (Core Mathematics 2) |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Topic | Binomial Theorem (positive integer n) |
| Type | Coefficient relationship between terms |
| Difficulty | Moderate -0.3 This is a straightforward binomial theorem question requiring standard application of the formula and simple algebraic manipulation. Part (a) is direct recall, part (b) involves setting up and solving a linear equation from coefficients, and part (c) is routine substitution. The multi-step nature and algebraic work make it slightly easier than average but still representative of typical C2 examination questions. |
| Spec | 1.04a Binomial expansion: (a+b)^n for positive integer n |
\begin{enumerate}[label=(\alph*)]
\item Write down the first four terms of the binomial expansion, in ascending powers of $x$, of $(1 + 3x)^n$, where $n > 2$. [2]
\end{enumerate}
Given that the coefficient of $x^3$ in this expansion is ten times the coefficient of $x^2$,
\begin{enumerate}[label=(\alph*)]
\setcounter{enumi}{1}
\item find the value of $n$, [2]
\item find the coefficient of $x^4$ in the expansion. [2]
\end{enumerate}
\hfill \mbox{\textit{Edexcel C2 Q27 [6]}}