Question

Use the transformation u=x+y, v=x-y to evaluate the double integral...?

Use the transformation u = x+y, v = x−y to evaluate ∫∫(R) of 4(x-y)e^(x+y)dA, where R is the square with
vertices (0, 1), (1, 0), (2, 1) and (1, 2)

Answer 1

i got 1<u<3 and -1<v<1 J=2
finally i got the answer is 0........

Answer 2

J=-1/2