Answer
$1$
Work Step by Step
We need to apply ratio test for a given series.
$\lim\limits_{n \to \infty} |\dfrac{a_{n+1}}{a_n}|=\lim\limits_{n \to \infty} |\dfrac{1}{(n+1)^2} \times \dfrac{n^{2}}{1}|=1$
This implies that the radius of convergence of the series is $1$.
