| Exam Board | Edexcel |
|---|---|
| Module | AEA (Advanced Extension Award) |
| Year | 2013 |
| Session | June |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Topic | Generalised Binomial Theorem |
| Type | Finding unknown power and constant |
| Difficulty | Challenging +1.2 This question requires setting up binomial coefficients with parameter n, equating them to find n, then applying convergence conditions. It involves algebraic manipulation and understanding of binomial expansion validity, but follows a standard approach for AEA-level binomial theorem problems without requiring particularly novel insight. |
| Spec | 1.04a Binomial expansion: (a+b)^n for positive integer n1.04d Binomial expansion validity: convergence conditions |
1.In the binomial expansion of
$$\left( 1 + \frac { 12 n } { 5 } x \right) ^ { n }$$
the coefficients of $x ^ { 2 }$ and $x ^ { 3 }$ are equal and non-zero.
\begin{enumerate}[label=(\alph*)]
\item Find the possible values of $n$ .\\
(4)
\item State,giving a reason,which value of $n$ gives a valid expansion when $x = \frac { 1 } { 2 }$\\
(2)
\end{enumerate}
\hfill \mbox{\textit{Edexcel AEA 2013 Q1 [6]}}