The function is

Differentiate the function with respect to .

Differentiate with respect to .

Find the inflection point by equating

Thus the inflection point is , Split the interval into , and

\ Interval \	Test Value	Sign of	Concavity
	\ \	\   \              \	Down
	\ \	\ \	Up

Thus the graph is concave down in the interval and concave up in the interval .

step 2:

Inflection points:

Inflection point 

Solution:

Inflection point 

The graph is concave down in the interval  

The graph is concave up in the interval .