$\"\"$

The function is $\"\"$ .

Apply derivative with respect to $\"\"$ .

$\"\"$

Quotient rule of derivatives : $\"\"$ .

$\"\"$

To find the critical numbers of $\"\"$ , equate $\"\"$ to zero.

$\"\"$

The function have critical numbers at $\"\"$ and $\"\"$ .

$\"\"$

Critical numbers : $\"\"$ and $\"\"$ .