I understand all the concepts of joint PDFs but I just can't get the right answer to this one. The function is:

f(x,y)=3x^(1/2)e^(-2y)

I need to find the probabilty over these two regions:

a)P(0 ≤x≤ 1; 3 ≤y≤ http://www.webassign.net/images/infinity.gif)

b) P({P({(x,y) | 2/3 ≤x≤ 1; 0 ≤y≤ http://www.webassign.net/images/infinity.gif)

2

Explanations would be much appreciated. Thanks