Step 1:
\The function has local maximum at
,
Since for all
close to 0, 
The local maximum value is
.
Step 2:
\The function has local minimum at
and 
Since for all
close to
, 
The local minimum value is 
Also for all
close to
, 
The local minimum value is 
The local minimum values are
and 
Solution:
\The local maximum value is 
The local minimum values are
and
.