SOLUTION: Prove by mathematical induction: ∑_(i=1)^n (3^i= 3(3^n-1)/2)

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Question 267871: Prove by mathematical induction: ∑_(i=1)^n (3^i= 3(3^n-1)/2)
Answer by Edwin McCravy(20060)   (Show Source): You can put this solution on YOUR website!



It's true for n=1, because:




Assume true for any k such that 

We want to prove that



Write that as the sum to k (for which we assume the formula holds,
plus the (k+1)st term or 

 

Edwin
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