Simplify (tanx+secx-1)/(tanx-secx+1)?

1 Answer
Apr 29, 2016

Please see the proof below.

Explanation:

(tanx+secx-1)/(tanx-secx+1)

Multiplying numerator and denominator by tanx+secx+1

= (tanx+secx-1)/(tanx-secx+1)xx(tanx+secx+1)/(tanx+secx+1)

= (tan^2x+tanxsecx+tanx+tanxsecx+sec^2x+secx-tanx-secx-1)/(tan^2x+tanxsecx+tanx-tanxsecx-sec^2x-secx+tanx+secx+1)

= (tan^2x+2tanxsecx+sec^2x-1)/(tan^2x+2tanx-sec^2x+1)

As sec^2x=tan^2x+1, above is equal to

= (tan^2x+2tanxsecx+tan^2x+1-1)/(tan^2x+2tanx-tan^2x-1+1)

= (2tan^2x+2tanxsecx)/(2tanx)

= (2tanx(tanx+secx))/(2tanx)

= tanx+secx