Question #0038f

1 Answer
Feb 18, 2017

see explanation

Explanation:

1secxtanx+1secx+tanx=2cosx

equate the denominator

secx+tanx+secxtanx(secxtanx)(secx+tanx)=2cosx

2secxsec2xtan2x=2cosx

make sec and tan become fraction

2secx1cos2xsin2xcos2x=2cosx

2secx1sin2xcos2x=2cosx

use trig identity so 1sin2x=cos2x

2secxcos2xcos2x=2cosx

2secx1=2cosx

21cosx=2cosx

2cosx=2cosx (verified)