Evaluate each of the following:

sec can be written as sec

Also, we know sec(2π –θ ) = sec(θ)

∴ sec = sec

∴ Now the given equation can be written as sec^{–1}sec

As sec^{–1}(sec x) = x

Provided x ϵ [0,π]–

∴ we can write sec^{–1}sec as .