UPSC NDA Math Model Paper 9

Given: f(x) = sec x
secx=

1

cos

x
Check where denominator becomes zero
cos x = 0
x = x = (2n + 1) π/2, n ∈ Z
∴ Given function is discontinuous at x = (2n + 1) π/2, n ∈ Z
Hence, option (3) is correct