(a) Given: 
= 
……….(i)
Now 
or 
or 
Therefore, we have sub-intervals are 
and 
For interval 
taking 
(say), from eq. (i),
> 0
Therefore, 
is strictly increasing in 
For interval 
taking 
(say), from eq. (i),
< 0
Therefore, is strictly decreasing in 
For interval 
taking 
(say), from eq. (i),
> 0
Therefore, is strictly increasing in
Hence, (a) is strictly increasing in 
and
(b) is strictly decreasing in