# Homework Help: Calculus 3 Change of Variables: Jacobians

1. Apr 30, 2009

### Wargy

1. The problem statement, all variables and given/known data
Evaluate $$\int$$$$\int$$e^xy dA, where R is the region enclosed by the curves: y/x=1/2 , y/x=2, xy=1, and xy=2.

2. Relevant equations
None?

3. The attempt at a solution
I have the region graphed and I'm currently working on acquiring the change of variables functions in x and y. I have attempted to solve the system of equations with u=y/x and v=xy to obtain these but I'm having some trouble. If I could be pointed in the right direction I would be greatly appreciative! Thanks.

2. May 1, 2009

### HallsofIvy

You have u= y/x and v= xy so y= xu. Substitute that into v= xy: v= x2u. Now solve for x.