The problem:

My attempt:

With |-9x^2| < 1, 9x < 1, x < 1/9

R = 1/9, I = (-1/9, 1/9)

Not sure if this is correct. Thanks

- Nov 21st 2011, 04:41 PMIntrusionFind power series representation and interval of convergence.
The problem:

My attempt:

With |-9x^2| < 1, 9x < 1, x < 1/9

R = 1/9, I = (-1/9, 1/9)

Not sure if this is correct. Thanks - Nov 21st 2011, 05:15 PMHallsofIvyRe: Find power series representation and interval of convergence.
That's a good way to start: you recognized that is the sum of the geometric series and here r= -9x^2[/tex]. However, does NOT give 9x< 1, it gives so that

- Nov 21st 2011, 10:13 PMIntrusionRe: Find power series representation and interval of convergence.
You're right, rookie mistake :D