The equations:

Check the Jacobian condition at the point (x,y,u,v) = (1,1,0,2) and show that this allows x and y to be defined implicitly as functions of u and v. At this point, compute the Jacobian D(x,y)/D(u,v).

Ok, a few problems with this one.

1) I don't know what the Jacobian condition is.

2) I don't know how to show that x and y are functions of u and v.

3) I'm still iffy with Jacobians and I'm not sure how to find the Jacobian matrix.

So, any tips to help me through this number?