00:01
All right, so let's say the line element on the surface of earth is given by some parameter a squared times d theta squared plus some function of theta squared times d phi squared.
00:16
And we're told that f of theta is equal to the sine of theta times one plus epsilon times the sine squared of theta.
00:26
So we wanna describe the shape of earth using these parameters.
00:31
So, all right, we're given that the equatorial radius of earth is, let's see, 6 ,378 kilometers.
00:42
And so if we take, if we look at the circumference around earth, it'll be the integral from zero to two pi of phi with theta fixed at, you know, pi over two.
00:55
All right, so, and so our line, this is the integral of ds.
01:00
And so if we actually look at what it gives us, this will give us a times one plus epsilon d theta, i believe, let me just make sure, or d phi, excuse me...