Question

Find the range of f(x) = sin^-1x  + cos^-1x + tan^-1x.

Answer 1

Given, f(x) = sin^-1x  + cos^-1x + tan^-1x.

The domain of f(x) is {-1, 1}

Now, f(1) = sin^-1(1) + sec^-1(1) + tan^-1(1)

= π/2 + 0 + π/4 = 3π/4