It's just too difficult to type.

I'll give you a slide, which contains all the information needed for this problem. Take a look. Really not good. I suggest you go to the bookstore to find a book on probability theory and mathematical statistics, which should have this problem, even the simplest basic version of economic mathematics. It is too difficult to type here.

I can only talk to you about my thoughts at most.

Find the expectation and variance of random variables X and Y first, then calculate the expectation with the expectation method of continuous random variables in the slide, and then find D(X) with D (x) = E (x 2)-E (x) 2.

Then use another formula in the slide to find e (x 2) and e (y 2).

Then d (xy) = e (x2y2)-e (xy) 2 = e (x2) * e (y2)-e (x) 2 * e (y) 2.

Just bring in the result of the previous goal 2.

Hehe, it's not difficult, but it's cumbersome. Be patient. Take your time. The workload is not small. Hehe, come on.