# How do you find the critical numbers of #y = cos x - sin x#?

##### 1 Answer

Jan 5, 2018

#### Explanation:

Take the derivative wrt x and set it to zero.

where

You can also inspect the plot of the function to verify the critical values. Click on maxima and minima of the graph to find their x values and compare to the solution.

y = cosx-sinx plot:

graph{(cosx- sinx) [-10, 10, -5, 5]}