00:01
Here we have d, which equals a set of points x, y, such that x is less than or equal to y, which is less than or equal to 4x.
00:12
And 1 is less than or equal to x, y, which is less than or equal to 2.
00:17
And we're going to let u equal x, y, and v equal y over x.
00:24
Then i'm going to go ahead and compute the double integral of x squared y squared dx dy.
00:31
So we know that y equals v times x, so that means u equals x times v times x, which is x squared v.
00:42
So that tells us that x is going to equal the square root of u divided by v, and y equals v times the square root of u over v, which equals the square root of u times v.
00:55
So now what we need to do is go ahead and compute the jacobian.
00:59
So the jacobian is going to equal the partial of x with respect to u, partial y with respect to u, and then partial x with respect to v, and then partial y with respect to v.
01:13
So this is going to then equal 1 over 2, the square root of u, v, the square root of u over 2 root u.
01:24
Sorry, there should be a v on top here.
01:27
And then we have negative u over 2, v to the 3 halves, square root of u, and then square root of u over 2 root v...