Jointly continuous random dependent variables

DotKite
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Homework Statement



Let X and Y be rv's with joint pdf

f(x,y) = 6(1-y) for 0≤x≤y≤1 and 0 elsewhere

find Pr(X≤3/4, Y≤1/2)

Homework Equations





The Attempt at a Solution



Ok I am having trouble with finding the right limits of integration for dependent variables. If we let the inner integral be for x would the limits be 0 to y? Then would y be 1/2 to 1?
 
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DotKite said:

Homework Statement



Let X and Y be rv's with joint pdf

f(x,y) = 6(1-y) for 0≤x≤y≤1 and 0 elsewhere

find Pr(X≤3/4, Y≤1/2)

Homework Equations





The Attempt at a Solution



Ok I am having trouble with finding the right limits of integration for dependent variables. If we let the inner integral be for x would the limits be 0 to y? Then would y be 1/2 to 1?

No. Have you drawn a picture of the region?
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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