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4 votes
Does the series 3+9+27+81+…. diverge or converge

User Jan ATAC
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2 Answers

5 votes
this series diverges
User Darwin
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5.0k points
1 vote

Given the series


3+9+27+81+\cdots

which is a geometric series with first term 3 and common ratio 3.

A geometric series conveges if and only if |r| < 1, where r is the common ratio. Here, r = 3 > 1. So, the given geometric series diverges.

User Paul Tyng
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6.1k points