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RootMath • View topic - Sum of 2i + 1
Page 1 of 1

Sum of 2i + 1

PostPosted: Wed Apr 06, 2011 9:14 pm
by mike
I got this question via YouTube, but I decided to answer it here because it is easier to type math.



The specific question is, why does this sum equal 35 not 31.

Answer:


If we break the sum into smaller pieces, which we are allowed to do, then the answer becomes more clear. The reason you might have gotten 31 is if you did something like this.