00:01
All right, the arc length formula is the integral of the square root of 1 plus the derivative squared, the x from first x to the second x.
00:17
So we're going to start at zero, and then we're going to go to some random second x.
00:21
Let's call it a.
00:25
All right, so first let's do all the algebra, and then it'll make the integration seem not so bad.
00:31
So f of x is 2x to the 3 halves.
00:38
So, oops.
00:41
So f prime of x is 3x to the 1 half.
00:49
So f prime of x squared is 3x to the 1ā2.
00:57
Which is 9x.
01:01
So then the square root of 1 plus f prime of x squared.
01:08
Is the square root of 1 plus 9x.
01:13
All right, so the arc length is the integral, 0 to a, 1 plus 9x, dx.
01:25
So let you be 1 plus 9x.
01:29
Then du is 9 dx...