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Determine whether the sum to infinity of the following G.P.s exist, if exists find them: 15,-25,45,-85,165,... - Mathematics and Statistics

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Question

Determine whether the sum to infinity of the following G.P.s exist, if exists find them:

`1/5, (-2)/5, 4/5, (-8)/5, 16/5, ...`

Sum
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Solution

`1/5, (-2)/5, 4/5, (-8)/5, 16/5, ...`

`"a" = 1/5, "r" = ((-2)/5)/(1/5)` = – 2

Since, | r | = | – 2 | > 1

∴ Sum to infinity does not exist.

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Chapter 2: Sequences and Series - Exercise 2.3 [Page 33]

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