UPSC NDA Math Model Paper 8

Here, tan(3x) =

sin(3x)

cos(3x)

Check where denominator become zero
We know cos x = 0, where x = (2n + 1) π/2
So for cos 3x = 0 where, 3x = (2n + 1) π/2
x = (2n + 1) π/6
∴ Given function is discontinuous at x = (2n + 1) π/6
Hence, option (3) is correct.