Step 1:

The function is .

Differentiate with respect to .

Find the critical number by equating to zero.

Roots of the quadratic equation are  .

Compare   with .

Substitute corresponding values in the

.

Step 2:

Critical points are .

Split the critical number in to three intervals as

Interval	Test Value	Sign of	Conclusion
		\   \ \	Increasing
		\   \ \	Decreasing
		\   \ \	Increasing

Thus, the function is increasing on the interval and .

And decreasing on the interval .

Solution:

The function is increasing on intervals and