The function is .
Find the inflection points by equating the second derivative to zero.
\Apply first derivative on each side with respect to .
Apply second derivative on each side with respect to .
Determine the values of at which
or
does not exist.
The inflection points are and
.
Substitute in
.
Substitute in
.
Therefore the inflection points are and
.
Test for concavity in the intervals ,
and
.
Intervals | \Test value | \ \
Sign of | \
Conclusion | \
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Concave upward | \
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\
| \
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Concave downward | \
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\
| \
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Concave upward | \
The function is concave upward in the intervals and
.
The function is concave downward in the interval .
The inflection points are and
.
The function is concave upward in the intervals and
.
The function is concave downward in the interval .