Q. 71

Question

Let z=( f(x, y))n. Show that zx=n( f(x, y))n-1fx  and zy=n( f(x, y))n-1fy .

Step-by-Step Solution

Verified
Answer

zx=n( f(x, y))n-1fxzy=n( f(x, y))n-1fy

1Step 1. Given information

A function, z=( f(x, y))n

2Step 2. Proofs of given partial derivatives

LHS=zx=( f(x, y))nxUsing power rule, chain rule and definition of partial derivatives, it follows that:=n( f(x, y))n-1fx=RHSSimilarly, for partial derivative with respect to y, we get,LHS=zy=( f(x, y))nyUsing power rule, chain rule and definition of partial derivatives, it follows that:=n( f(x, y))n-1fy=RHS