The graph of a function z=f(x,y) can always be parametrized as (x,y,f(x,y)). Show that in this case the "old way" (using the derivative) and the "new way" (Parametrizing the surface) for finding the tangent plane at a point always agree.
I have no idea how to do this problem. I think he wants us to show that two different ways lead to the same tangent plane at a point. one is using the derivative, the second is doing it via surfaces. Can someone run me through the steps? Thanks in advance!