1. The problem statement, all variables and given/known data So the last thing we got to learn before studying for finals ...... 2. Relevant equations ... was converting something like dx/dt = F(x,y) dy/dt = G(x,y) into a .... 3. The attempt at a solution ... system of equations like (x' y')T = J * (x y)T, where J is the Jacobian Matrix [ (∂F/∂x ∂G/∂x)T , (∂D/∂y ∂G/∂y)T ]. I'm just wondering why exactly that works. Could someone show me a proof or something? Being the weird dude I am, I need to know these things.