Which function has a domain of all real numbers except x=npi, where n is any integers

The domain of the function given are:
y=cot x
{x∈R: πn<x<π(n+1)} where n any integer

y=csc x
{x∈R: πn<x<π(n+1)}  where n any integer

y=cos x 

R (all real numbers)

y=sec x

{x∈R:π(n+1/2)<x<π(n+3/2)} where n is all integers.

from above we see that the the function that has a domain of all real numbers except npi is y=cot x and y=csc x