The curve is
and the interval is
.
The surface area formula for rotation about the
-axis is,
.

Differentiate the curve with respect to
.

Apply formula:
.
.
Substitute corresponding values in
.
The surface area is
.
Let
, then
.
Evaluating boundaries :
\If
, then
.
If
, then
.
Substitute corresponding values in
.

Apply formula:
.

Hyperbolic sine function:
.

The exact area of the surface by rotating the curve about the
-axis is
square units.
The exact area of the surface by rotating the curve
about the
-axis is
square units.