(a)
\The function is .
Find the critical numbers by applying derivative.
\Apply derivative on each side with respect to .
Equate the derivative to .
Therefore the critical numbers are and
.
(b)
\Consider the test intervals to find the interval of increasing and decreasing.
\Test intervals are ,
and
.
Test interval | \Test value | \Sign of ![]() | \
Conclusion | \
![]() | \
![]() | \
\
| \
Increasing | \
![]() | \
![]() | \
\
| \
Decreasing | \
![]() | \
![]() | \
\
| \
Increasing | \
The function is increasing on the intervals
and
.
The function is decreasing on the interval
.
(c)
\Use first derivative test to identify all relative extrema.
\ changes from positive to negative at
. [From (b) ]
Therefore according to first derivative test , the function has maximum at .
The function has a relative maximum at
.
Find .
So the function has relative maximum at
.
changes from negative to positive at
. [From (b) ]
Therefore according to first derivative test , the function has minimum at .
The function has a relative maximum at
.
Find .
So the function has relative minimum at
.
(d)
\Graph :
\Graph the function :
Observe the graph :
\The function has critical numbers at and
.
The function is increasing on the intervals
and
.
The function is decreasing on the interval
.
The function has relative maximum at
.
The function has relative minimum at
.
(a) The function has critical numbers at and
.
(b)
\The function is increasing on the intervals
and
.
The function is decreasing on the interval
.
(c)
\The function has relative maximum at
.
The function has relative minimum at
.
(d) Graph of the function is
.