How to find E(XY) when X and Y are NOT indepdant?

by laura_a
Tags: indepdant
 P: 2 You can use the definition of an expectation. E(XY) = $$\oint\oint$$x*y*f(x,y) dy dx Or you could argue that since the function is symmetric about 0 and the intervals [-1, 1] are centred about 0 that E(XY) = 0
 HW Helper P: 1,377 The density isn't symmetric about zero. Laura, for any joint continuous distribution, whether or not $$X, Y$$ are independent, you can find $$E[XY]$$ as $$\iint xy f(x,y) \, dxdy$$