cot(–θ) is –cot(θ)

∴ The equation given above becomes cot^–1(–cot)

cot.

Therefore

Let cot^–1() = y

⇒ cot y =

= cot

The range of principal value of cot^–1is (0, π)

and cot

∴ The value of cot^–1(cot) is .