# The chain rule (PDE)

1. ### Kork

33
Im new on the forum, so I hope you guys will have some patience with me :-)

I have a question about the chain rule and partial differential equations that I cant solve, it's:

Write the appropriate version of the chain rule for the derivative:

∂z/∂u if z=g(x,y), where y=f(x) and x=h(u,v)

I have tried to do a dependence chart of it, but it's just not working for me.

Thank you very much.

2. ### alan2

219
∂z/∂u=(∂z/∂x)(∂x/∂u)+(∂z/∂y)(dy/dx)(∂x/∂u)

Draw a diagram. It is pretty straightforward.