3 (ii)
Rationalised 2023-24
INVERSE TRIGONOMETRIC FUNCTIONS     23
its range as the set R – (–1, 1) Actually, secant function  restricted to any of the
intervals [–π, 0] – { 2
−π }, [0, ] –
π2
 
π
 
 
, [π, 2π] – { 3
2
π } etc , is bijective and its range
is R – {–1, 1} Thus sec–1 can be defined as a function whose domain is R– (–1, 1) and
range could be any of the intervals [– π, 0] – { 2
−π }, [0, π] – { 2
π }, [π, 2π] – { 3
2
π } etc