# How do you simplify the expression #(secx-1)(secx+1)#?

##### 1 Answer

#### Explanation:

#(sec x-1)(sec x +1) =sec^2 x-1#

The one trig identity to remember is

#sin^2x +cos^2x =1#

Divide through by

#tan^2x + 1 = sec^2x#

Rearrange

And you have your answer