$\"\"$

The function is $\"\"$ .

Critical number :

A critical number of a function $\"\"$ is a number $\"\"$ in the domain of $\"\"$ such that either $\"\"$

or $\"\"$ does not exist.

The function $\"\"$ is differentiable at all values of $\"\"$ because it is a polynomial.

Differentiate $\"\"$ on each side with respect to $\"\"$ .

$\"\"$

Graph :

Graph the derivative function $\"\"$ :

$\"\"$

Observe the graph.

Critical numbers are the points where derivative of the function is zero.

The derivative of the function is zero at $\"\"$ and $\"\"$ .

The critical numbers are $\"\"$ and $\"\"$ .