What is the range of sec x?

1 Answer
Sep 26, 2014

The range of secx is (-infty,-1]cup[1,infty).

Let us look at some details.

We know

|cosx| le 1

by taking the reciprocal,

Rightarrow |secx|=1/|cosx| ge 1

(Note that we need to switch the direction of inequality.)

Hence, its range is (-infty,-1]cup[1,infty).