# Math Help - Partial Differentiation

1. ## Partial Differentiation

Hi guys could you please help me with this question-

For an arbitrary function f = f(u, v) show that

1/x(df/dx) + 1/y(df/dy) = 4(df/du)

where u = x^2 + y^2, v = x^2 − y^2,

x not = 0 and y not = 0

2. Originally Posted by rologolfer
Hi guys could you please help me with this question-

For an arbitrary function f = f(u, v) show that

1/x(df/dx) + 1/y(df/dy) = 4(df/du)

where u = x^2 + y^2, v = x^2 − y^2,

x not = 0 and y not = 0
By the chain rule, $\frac{\partial f}{\partial x}= \frac{\partial f}{\partial u} \cdot \frac{\partial u}{\partial x}+\frac{\partial f}{\partial v} \cdot \frac{\partial v}{\partial x}$.
Does this help?

3. Thanks a lot, thats great!