If it is already given that X1 and X2 are independent R.V. each having p.d.

f(x) = { e^-x , x > 0

{ 0 , otherwise

How would one go about showing that R.V. (s) R.V.s Y1 and Y2 are independent when Y1 = X1 + X2, Y2 =

Do I need the abstraction of Y1 and Y2 or can I just leave it in terms of X? I'm not sure if thats the right question. The additional R.V.s are throwing me off.

Oh, and can someone give me a link to a tutorial or listing of the Math Markup used to display Math notation so my next thread or answer can look better.

Thank you