SOLUTION: Using math of induction show that 2^n + (-1)^n+1 is divisible by 3

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Question 1137651: Using math of induction show that 2^n + (-1)^n+1 is divisible by 3
Answer by math_helper(2461)   (Show Source): You can put this solution on YOUR website!
Base case: n=1


Hypothesis: Assume is divisible by 3 for n=k

Step case: Let n=k+1:

We know is divisible by 3 (by hypothesis)


Look at V-W:


=

The last two terms combine to -2 when k is odd, +2 when k is even, factor
out 2:
=

Noting that :
=

By the hypothesis, the factor is divisible by 3
We know W is divisible by 3 and V-W is also divisible by 3, so V = (W)+(V-W) is also divisible by 3.

DONE


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