In the expansion of $\left(x+\dfrac{1}{x}\right)^n$ where $n$ is even, if the $(r+1)$th term is free of $x$, then $r$ eq

Question

In the expansion of $\left(x+\dfrac{1}{x}\right)^n$ where $n$ is even, if the $(r+1)$th term is free of $x$, then $r$ equals —

Accepted Answer

$\dfrac{n}{2}$

Answer

$0$

Answer

$n$

Answer

$2n$

In the expansion of (x+1x)n\left(x+\dfrac{1}{x}\right)^n(x+x1​)n where nnn is even, if the (r+1)(r+1)(r+1)th term is free of xxx, then rrr equals —