1. The problem statement, all variables and given/known data Hey, i ve got problem with a few partial derivative problems. 1.I have a function T(x,t) Prove that dT/dt=∂T/∂t +∂T/∂x dx/dt 2.Let u(x,y) and y(x,u) be continous, differentiable functions. Prove that ∂u/∂z=∂u/∂z ∂y/∂z 3 Let r(q1,q2,...qn) be a function of place depending on n coordinates. Show that ∂r/∂q=derivative of r/derivative of q , 2. Relevant equations 3. The attempt at a solution Well, the first one i tried to prove chain rule for partial derivatives but i failed. I also cannot find one in the Web. Second comes from Leibniz notation for derivatives - but again I cant prove it myself or find a prove. Third- well i dont have a clue.