Compute the Jacobian of the following functions

Question

Solve for x and y in terms of u and v, then compute the Jacobian partial (x,y) /partial(u,v).

The correct answer is that this gives the number 0.5. I have calculated the determinant, which I believe is correct. I have calculated 0.5(u^2-v^2). How do I get from this to 0.5?

Answer 1

There is no information about x(u,v) and y(u,v). Also, the question must ask for the Jacobian determinant at a point, probably.