(a).
\The perimeter of rectangule is
.
Consider length of rectangular is
and width of the rectangular is
,Then perimeter of rectangular is
.
The area of rectangle
is
.
if
then
.
Substitute
in the equation
.

.
The area of rectangle as a fucntion of width
is
.
(b).
\Find the area of rectangle when width is maximum.
\
is the form of general quadratic equation
Therefore
and
.
The maximum area occurs at
.

The maximum width is
.
(c).
\Find the maximum area.
\Substitute
in the function
.



The maximum area is
.
(a).
(b).The maximum width is
.
(c).The maximum area is
.