The function is
and
.
Area of the region is
.
Where
and
.
Consider number of subintervals be
.


Substitute
in
.




Apply summation formula
.

As
, then
.



.
Area of the region is between
and
-axis is
sq-units.
Graph :
\Graph the region :
\Area of the region is
sq-units.
Area of the region is
sq-units.