00:01
Okay, so first we're going to multiply the x and the 6 minus x to get 6x minus x squared.
00:10
Factor out a minus sign, so x squared minus 6x, and then let's complete the square in there.
00:17
So half of minus 6 squared.
00:19
I'm going to add 9 and subtract 9.
00:22
So i have minus x minus 3 squared minus 9 or 9 minus x minus 3 squared minus 3 squared.
00:33
So now i have the square root of 9 minus x minus 3 squared dx.
00:41
So let's let x minus 3 squared be 9 sine squared.
00:47
So that 9 minus x minus 3 squared, oh, square root would be the square root of 9 minus 9 sine squared.
00:58
So it would be the square root of 9 times 1 minus sine squared, square root of 9 cosine squared, which would be 3 cosine...