interval/radius of convergence

[harsh linden]

i have no idea of where to start on this one lols

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[shrewd vortex]

@harsh linden

[harsh linden]

how did u do that?

[mental burrow]

use the ratio test, find $\lim_{n\to\infty}\abs{\frac{a_{n+1}}{a_n}}$ where the power series converges if $\lim_{n\to\infty}\abs{\frac{a_{n+1}}{a_n}}<1$

[rocky anchor]

Anonymous

[mental burrow]

be sure to check the endpoints as it could converge there too

but if what carbon said above is the answer its pretty clear in the limit as n gets large, the function gets unbounded and ya so it wouldn't converge at the end pts either

[harsh linden]

thanks so much!! :)

+close