Hi guys!
I want to define for the part $a)$ $$x(u,v); \ \ y(u,v)$$ but in the problem change the order in the components. I calculate the Jacobian matrix and obtain an equation that I not comprhend because it remains in terms of the same function. I think that $a)$ and $b)$ are the same problem.
I appreciate any help and suggestions you can give me.