3 (i), (ii) Also, since sec x = 
1
cos x , the domain of y = sec x is the set R – {x : x = (2n + 1) 2
π ,
n ∈ Z} and range is the set R – (–1, 1) It means that sec (secant function) assumes
all real values except –1 < y < 1 and is not defined for odd multiples of 2
π If we
restrict the domain of  secant function to [0, π] – { 2
π }, then it is one-one and onto with
Fig 2