- #1
eprparadox
- 138
- 2
Homework Statement
Given f(x, y, z) = 0, find the formula for
[tex]
(\frac{\partial y}{\partial x})_z
[/tex]
Homework Equations
Given a function f(x, y, z), the differential of f is
[tex]
df = \frac{\partial f}{\partial x}dx + \frac{\partial f}{\partial y}dy + \frac{\partial f}{\partial z}dz
[/tex]
The Attempt at a Solution
We know that f(x, y, z) = 0 so using above, I get
[tex]
df = \frac{\partial f}{\partial x}dx + \frac{\partial f}{\partial y}dy + \frac{\partial f}{\partial z}dz
= 0
[/tex]
We also know that we are finding the partial with constant z so I set dz = 0. I then divided by dx throughout and solve for [itex] \frac{\partial y}{\partial x} [/itex].
My final answer is
[tex]
(\frac{\partial y}{\partial x})_z = -\frac{\frac{\partial f}{\partial x} }{\frac{\partial f}{\partial y} }
[/tex]
I just wanted to confirm that I'm doing things correctly in finding this partial derivative.
Thanks!