6)

\

Step 1:

\

The function is \"\".

\

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

\

\"\"

\

Find the critical points.

\

Since \"\" is a polynomial it is continuous at all the point.

\

Thus, the critical points exist when \"\".

\

Equate \"\" to zero.

\

\"\"

\

\"\", \"\"and \"\".

\

The critical points are \"\", \"\"and \"\".

\

Substitute \"\" in \"\".

\

\"\"

\

Substitute \"\" in \"\".

\

\"\"

\

Substitute \"\" in \"\".

\

\"\"

\

The critical points are \"\" and \"\".

\

The test intervals are \"\", \"\", \"\" and \"\".

\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
Interval Test Value Sign of \"\"Conclusion
\"\"\"\" \

\"\"

\
Decreasing
\"\" \"\" \

\"\"

\
Increasing
\"\" \"\" \

\"\"

\
Decreasing
\"\" \"\" \

\"\"

\
Increasing
\

The function is increasing on the intervals \"\" and \"\".

\

The function is decreasing on the interval \"\" and \"\".

\

Step 2:

\

\"\".

\

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

\

\"\"

\

Find the inflection points.

\

Equate \"\" to zero.

\

\"\"

\

The inflection points are at \"\".

\

Substitute \"\" in \"\".

\

\"\"

\

Substitute \"\" in \"\".

\

\"\"

\

Inflection points are \"\" and \"\".

\

The test intervals are \"\", \"\" and \"\".

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

Interval

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

Up

\
\

The graph is concave up on the interval \"\" and \"\".

\

The graph is concave down on the interval \"\".

\

The inflection point is \"\".

\

Step 3:

\

Graph the function \"\" :

\

Graph :

\

1). Draw a coordinate plane.

\

2). Plot the inflection points and critical points.

\

3). Connect the plotted points.

\

\"\"

\

Solution: \ \

\

The function is increasing on the intervals  \"\" and \"\".

\

The function is decreasing on the intervals \"\" and \"\". \ \  

\

The graph is concave up on the interval \"\" and \"\".

\

The graph is concave down on the interval \"\".

\

\ \

\

Graph of the function \"\" :

\

\

\"\".