The maximum vaue of function
on set of all real numbers are satisfies the 
The function is 
Let 




and 
Substitute
.
and
.
.
and
.
and
and 
At 


The function
is maximum and
is minimum.
At 


The function
is maximum and
is minimum.
The function
is maximum and
is minimum in the interval
.
The function
is maximum and
is minimum in the interval
.