# Let {eq}z = \cos(x^5 + y^5) {/eq}. Find {eq}\displaystyle \dfrac {\partial z}{\partial y} {/eq}.

## Question:

Let {eq}z = \cos(x^5 + y^5) {/eq}. Find {eq}\displaystyle \dfrac {\partial z}{\partial y} {/eq}.

## Partial Derivatives:

We can differentiate a wide variety of functions, even if they have more than one variable. However, since we can only differentiate with respect to one variable at a time, we need to treat the remaining variables in the function as coefficients and constants.