1 (i)
Rationalised 2023-24
INVERSE TRIGONOMETRIC FUNCTIONS     21
restricted to any of the intervals [– π, 0],  [0,π], [π, 2π] etc , is bijective with range as
[–1, 1] We can, therefore, define the inverse of cosine function in each of these
intervals We denote the inverse of the cosine function by cos–1 (arc cosine function)