Radius of convergence of sum of squared coefficients

[betty2301]

Homework Statement

Calculate the radius of convergence of $\sum_{n=0}^\infty a_{n}^{2}z^{n}$
let $\sum_{n=0}^\infty a_{n}z^{n}RADIUS R$

Homework Equations

$\limsup|a_n|^{\frac{1}{n}}=\limsup |\frac{a_{n+1}}{a_n}|$

The Attempt at a Solution

the latex is killin me please help....

 

[snipez90]

Again this should be straightforward. Just compute one of the limits under relevant equations using the coefficients for your new power series and relate this to R.