- #1
Jbreezy
- 582
- 0
Homework Statement
Find the radius of convergence and the interval of convergence
Homework Equations
A_n = Ʃ sum n =1 to infinity [((-1)^n) x^(2n+1)]/(2n+1)!
The Attempt at a Solution
All I thought was to use the ratio test so I did A_(n+1) /A_n
= ((x^(2n+1))/(2n+1)!) ( (2n+1)!)/ [x^(2n+1)]
I got |x^2| limit n ---> |x^2 / 4n^2 +10n +6 | when I simplified and such. So the limit is equal to 0 so my interval of convergence is 0 ? and R = 0?