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The interval of convergence of the series

the summation of (x + 1)^k / (k^2) [from k=1 to infinity] is?

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I tried using the ratio test, but I wasn't able to cross enough factors out. Is there another test I can use? Please help!!!

2007-07-05 15:42:03 · 2 answers · asked by thisusernameisthebes 2 in Science & Mathematics Mathematics

SORRY! Forgot to add this:

A. 0 < x < 2
B. 0 < x < 2 (including 0 and 2)
C. -2 < x < 0 (including 0)
D. -2 < x < 0 (including -2)
E. -2 < x < 0 (including -2 and 0)

2007-07-05 15:52:33 · update #1

2 answers

from looking at it after K>2 the numerator will blow up so the absolute value must be kept equal to or less than one.

this leaves
x+1<1, x+1>-1 -> x<0, x>-2, -2

2007-07-05 15:55:19 · answer #1 · answered by lifes3ps 1 · 1 0

The interval appears to be -10, it diverges. [on second thought, try E], for the same reason

2007-07-05 22:50:13 · answer #2 · answered by cattbarf 7 · 0 0

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