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Question
Determine whether the sum to infinity of the following G.P.s exist, if exists find them:
`-3, 1, (-1)/3, 1/9, ...`
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Solution
Here, a = – 3, r = `-1/3`
Since | r | = `|-1/3| = 1/3 < 1`, the sum to infinity of this G.P. exist and
S = `"a"/(1 - "r")`
= `(-3)/(1 - (-1/3))`
= `(-3)/((4/3))`
= `-9/4`.
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