Given Definite Integral can be written as:

……(1)

Let us assume y = tan^-1x

Differentiating w.r.t x on both sides we get,

⇒ d(y) = d(tan^-1x)

……(2)

Upper limit for the Definite Integral:

⇒ x = 1 ⇒ y = tan^-1(1)

……(3)

Lower limit for the Definite Integral:

⇒ x = 0 ⇒ y =tan^-1(0)

⇒ y = 0……-(4)

Substitute (2),(3),(4) in the eq(1) we get,

We know that:

We know that:

[here f’(x) is derivative of f(x)).