Attempting a multivariable question.
$$f(x,z) = 6z^3 - 5(x-z)^2 - 4x$$
I want to do the various first and second derivatives of this ($dy/dx$,$dy/dx$, $d^2y/dxdz$) but I'm stuck on the first derivative. My issue is with the middle term "$5(x-z)^2$". Do i use chain rule and make it "$10(x-z)^2$" or do i use power rule and it just becomes $10(x-z)$?