The integral is
.
Rewrite the integral.
\
.
Trigonometric identity:
.


.
.
Consider the antiderivative function by taking
as
.
Graph :
\Graph the integrand function
and its antiderivative
.

Observe the graph,
\When
is negative, then
is decreasing and
is positive, then
is increasing.
Hence the curve
is derivative of the curve
.
Therefore,
is antiderivative of the integrand function
.
.
Graph :
\
.