# Verifying a taylor series

1. Sep 5, 2012

### ThatOneGuy45

1. The problem statement, all variables and given/known data
For this problem I am to find the values of x in which the series converges. I know how to do that part of testing of convergence but constructing the summation part is what I am unsure about.

I am given the follwing:
1 + 2x + $\frac{3^2x^2}{2!}$ +$\frac{4^3x^3}{3!}$+ ...

2. Relevant equations
I looked up online about the taylor series expansion for ex because I noticed it looked familiar and compared it with the series

The taylor series for ex is:
1 + x + $\frac{x^2}{2!}$ +$\frac{x^3}{3!}$+ ...=Ʃ$^{∞}_{n=0}$$\frac{x^n}{n!}$

3. The attempt at a solution
What I did was pretty much just put $\frac{(n+1)^nx^n}{n!}$ and checked the terms to see if it works. It seems to work but I am just a bit unsure. I haven't worked with this stuff in a while so I just want to be sure if I did that part right.

Last edited: Sep 5, 2012
2. Sep 6, 2012

### clamtrox

That looks correct. You should be able to see if it converges using the ratio test, just be careful with the limit.