SOLUTION: The sum of the infinite geometric series -3+ 1 -1/3 +1/9 +...is? Thanks!

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Question 742214: The sum of the infinite geometric series -3+ 1 -1/3 +1/9 +...is?
Thanks!

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!



Sn+=+a1%281-r%5En%29+%2F+%281-r%29........... In this equation,
"Sn" is the sum of the geometric series, "a%5B1%5D" is the first term in the series, "n" is the number of terms and "r" is the ratio by which the terms increase
given:
-3%2B+1+-1%2F3+%2B1%2F9+++..
the ratio by which the terms increase is -1%2F3 (if you multiply first term by -1%2F3 you get second term 1,if you multiply second term by -1%2F3 you get %281%29%28-1%2F3%29=-1%2F3, etc.)
so, r=-1%2F3, a%5B1%5D=-3 and n={ 1,2,3,.... }