The function is .
Observe the graph :
\The interval is .
Consider .
Differentiate with respective to .
at
.
Surface area:
\Let is a continuous derivative on the interval
.
The surface area is ,
is the distance between
and the axis of revolution.
Where is
and
.
Substitute and
in
.
.
The surface area is .
Consider .
Differentiate with respective to .
.
If then
.
If then
.
Substitute the corresponding values in .
.
.
.