
Urgent help needed
Hi
I have this calculus question question which has caused me some trouble:
$\displaystyle z = y + f(x^2  y^2) $
Where f is diffentiable
I need to show that
$\displaystyle y \frac{\partial z}{\partial x} + x \frac{\partial z}{\partial y} = x$
How do I show that?
Is it by using the chain rule ?
/Fred

Yes, use the chain rule. For example, partial d/dx of f(x^2y^2) is f'(x^2y^2) times partial d/dx of (x^2  y^2). Here f' denotes the derivative of f as a function of a single variable.