Question 1035633
For both, the range is all real numbers.  The secant is the reciprocal of the cosine, and the range of the latter is between -1 and 1.  The reciprocal of all numbers in between is infinite.
The domain is where x cannot be pi/2 or 3pi/2 or (2n+1)pi/2, for here, the cosine x is 0.
that is the y=sec x domain.
the y=sec (2x) domain is half that, where x cannot be pi/4, 3pi/4 or (2n+1)pi/4.