00:01
Okay, so we want to use mathematical induction to show that the following is true.
00:04
So let's start with condition 1.
00:06
We need to show that n is equal to 1 is true.
00:09
So starting with our left hand side, we have 2 times 1, minus 1, and then we have 2 times 1.
00:15
So that's equal to a 1 times 2, which is equal to 2.
00:19
And is that equal to our right hand side? well, let's see.
00:25
So that's equal to a 3, and this is a 2.
00:29
So we get 6 over 3, which is equal to 2.
00:32
So we see that this is true.
00:34
And now let's move on to condition 2.
00:37
So in this case, we need to assume that n is equal to k is true.
00:43
So let's write out n is equal to k.
00:45
So we have 1 times 2 and then 3 times 4, so on, up to 2k minus 1 times a 2k.
00:55
And that's going to be equal to what we have up there.
00:58
So instead of an n, we have a k.
01:05
Okay.
01:05
And now we want to show that n is equal to k plus 1 is true.
01:09
So let's write out how it would luck if it was true.
01:12
We'd have 1 times 2 plus 3 times 4 all the way up to.
01:17
I'm going to include our k term.
01:20
So we have that should be a 2k minus 1 times a 2k and then plus our k plus 1.
01:29
So this is a 2k plus 2 minus 1.
01:31
So we get 2k plus 1.
01:33
And then we have a 2k plus 2.
01:38
So that's going to be equal to 1 over 3, k plus 1, k plus 2, and then 4k plus 4 minus, so we get 4k minus, or sorry, that's a plus 3.
01:50
Okay, so starting with our left hand side, let's notice that this entire portion is n is equal to k, and we assume that n is equal to k is true, so we can rewrite it like so...