00:03
Okay, so to prove this formula by induction, the first step to do our base case, which is that n equals 1.
00:12
This one's pretty easy because our only term for n equals 1 is just going to be n, which is 1, and then it's going to be equal to n squared, or 1 squared, which is just 1.
00:27
So our base case works.
00:32
Our inductive case is a little harder.
00:34
So if we let n equal k, we'll get 1 plus 2, everything up to k minus 1 to k back down again.
00:55
And that's going to equal k squared.
01:01
Now, how we're going to make this the next term, our final term, notice, is in the middle.
01:14
It's like a pyramid.
01:17
So in order to get our next term, we're going to need plus k.
01:24
And plus k plus 1...