The LHS looks the most complicated, but what do you do with it?

X

Prove the trig identity cosx/(secx+tanx)= 1-sinx

Relevant page
<a href="/analytic-trigonometry/1-trigonometric-identities.php">1. Trigonometric Identities</a>
What I've done so far
The LHS looks the most complicated, but what do you do with it?

Re: Prove the trig identity cosx/(secx+tanx)= 1-sinx

`LHS = cosx/(secx+tanx)`
`=(cos x)/(1/(cosx) + (sinx)/(cosx))`
I multiply top and bottom by `cosx`:
`=(cos^2 x)/(1 + sinx)`
It doesn't look like the RHS yet

Re: Prove the trig identity cosx/(secx+tanx)= 1-sinx

Why? Because (experience tells me) it will help us get it in the right form.

X

OK, good so far.
This uses a trick that you can see on the page you originally came from:
<a href="/analytic-trigonometry/1-trigonometric-identities.php">1. Trigonometric Identities</a>
You need to multiply top and bottom by `1-sinx`.
Why? Because (experience tells me) it will help us get it in the right form.

Re: Prove the trig identity cosx/(secx+tanx)= 1-sinx