The
graphs of y = cos x and y = cos–1x are given in Fig 2 2 (i) and (ii) Fig 2 2 (ii)
Let us now discuss cosec–1x and sec–1x as follows:
Since, cosec x = 
1
sin x , the domain of the cosec function is the set {x : x ∈ R and
x ≠ nπ, n ∈ Z} and the range is the set {y : y ∈ R, y ≥ 1 or y ≤ –1} i