Consider the expansion of $ (3 + x^2)^{n + 1}$, where $n \in \mathbb{Z}^+$. Given that the

Question

Consider the expansion of $ (3 + x^2)^{n + 1}$, where $n \in \mathbb{Z}^+$. Given that the coefficient of $x^4$ is $20412$, find the value of $n$.[5]

Accepted Answer

$n = 7$

2021 May TZ1 P2 Q6