(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

[n=0 to ∞] ∑x^{2n}/n!

2. Relevant equations

The ratio test

3. The attempt at a solution

So, here is the ratio of of the (n+1)^{th}term to the n^{th}term:

| [x^{2(n+1)}/(n+1)!] / [x^{2n}/n!] | =

| [x^{2n}x^{2}/(n+1)!] * [n!/x^{2n}] | =

| x^{2}/n |, which will be will be less than one when n is big enough.

So this converges for all x, right?

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# Homework Help: Determine the interval of convergence for

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