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 :
\.