## Trig Functions question

1. The problem statement, all variables and given/known data

Simplify: cosx / (1+sinx)

2. The attempt at a solution

1 / (sec x)(1+sin x)

1 / (sec x + (sin x / cos x))

1 / (sec x + tan x)

I know that the answer is sec x - tan x but don't know how to get there.

Any help would be appreciated.
 PhysOrg.com science news on PhysOrg.com >> King Richard III found in 'untidy lozenge-shaped grave'>> Google Drive sports new view and scan enhancements>> Researcher admits mistakes in stem cell study
 Do you know what the value of $$sec^2x-tan^2x$$ is? The difference of two squares helps too.
 sec^2 (x) - tan^2 (x) = 1 but nothing's squared in the problem

## Trig Functions question

Not until you do some multiplying.

Do you understand what I mean by the difference of two squares?
 Recognitions: Homework Help Science Advisor You could also just multiply top and bottom of your given expression by (1-sin(x)) and expand. It's really the same thing as jing is suggesting.
 OK, So it's (sec x - tan x) / (sec x + tan x)(sec x -tan x) = (sec x - tan x) / 1 = sec x -tan x Thank you so much!!