$\"\"$

The function is $\"\"$ , $\"\"$ .

Find the critical numbers by applying derivative.

$\"\"$

Equate it to zero .

$\"\"$

For $\"\"$ .

$\"\"$ .

For $\"\"$ .

$\"\"$ .

Therefore the critical numbers are $\"\"$ and $\"\"$ in the interval $\"\"$ .

Therefore the function have only one test interval $\"\"$ .

\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \

Test intervals	\ Test value \	\ sign of $\"\"$ \	conclusion
$\"\"$	$\"\"$	\ $\"\"$ \	Decreasing

The function $\"\"$ is decreasing on the entire interval $\"\"$ .

$\"\"$

The function $\"\"$ is decreasing on the entire interval $\"\"$ .