Evaluate the following integrals:

Assume tan ^{- 1}x = t

d(tan ^{- 1}x) = dt

⇒

Substituting t and dt in above equation we get

⇒

⇒

⇒

But t = tan ^{- 1}x

⇒ 2(tan ^{- 1}x)^1/2 + c.