I need to evaluate the following integral :
I know that I need to change the variables by using substitution $u = x+y$ and $v =y-x$ but I am confused about changing the limits of the new integral ,
I am trying to get the limits by drawing the graph of given limits in (x,y) and then , draw the corresponding graph in u-v plane using given equation,
But I am still not getting it .
Can please someone explain on how to change limits of this integral, and how should I proceed while tackling such problems of the same kind ?