# Math Help - partial Derivative

1. ## partial Derivative

What is the partial derivative with respect to y of squareRoot(x-y)? Thanks.

2. $\displaystyle f = \sqrt{x-y}$

$\displaystyle f = (x-y)^\frac{1}{2}$

Hold $x$ as constant

$\displaystyle \frac{\partial f}{\partial y} = \frac{1}{2}(-1)(x-y)^\frac{-1}{2}$

$\displaystyle \frac{\partial f}{\partial y} = \frac{-1}{2\sqrt{x-y}}$