Mathematics · important
Coefficient of \(x^{n-r}\) in \((x+a)^n\) for JEE
General term and middle term and simple applications
Formula
\[\text{Coeff. of }x^{n-r}\text{ is }{n\choose r}a^r\]
Variables: \(r=0,1,\dots,n\).
Direct coefficient extraction in standard form.