Answer:
secant and cosecant have no zeroes.
Step-by-step explanation:
We have in total 6 trignometric functions as
sine, cosine, tangent, cosecant, secant, or cotangent.
Of these we have
sin is 0 for all multiples of pi
cosec = 1/sin cannot be zero since sine value is always finite lies between -1 and 1.
Similarly sec = 1/cos cannot be zero since cosine value is always finite lies between -1 and 1.
cotangent can be 0 for odd multiples of pi/2
Hence answer is only
secant and cosecant
