The integral is .

Consider .

Apply derivative on each side.

Substitute  and  in the integral.

 .

Replace  in above expression.

.

.

Consider the anti derivative function as  and integrand function as .

Take , then .

Graph:

Graph the integrand function and anti derivative function.

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 .

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