The functions are and .

Consider .

Fundamental theorem of calculus :

If is continuous on , then the function is defined by  is continuous on  and differentiable on , then .

From the fundamental theorem of calculus, part 1:

.

Therefore, .

Consider .

Consider .

Differentiate on each side with respect to .

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Apply derivative on each side with respect to .

Rewrite the expression using chain rule.

.

.

From the fundamental theorem of calculus, part 1:

.

Here .

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Replace and in above expression.

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We have, .

Substitute in above expression.

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