## anonymous 4 years ago trig identity

1. anonymous

$\huge \frac{ sinx-2sinx^3 }{ 2\cos^3x-cosx } = tanx$

2. anonymous

is this proving? or simplifying?

3. anonymous

proving

4. anonymous

the left side is confusing me to the max

5. anonymous

|dw:1353299892857:dw|

6. anonymous

The first step I factored out sinx and cosx The second step I used the double angle formula for cos2x

7. anonymous

o.O you made it look so easy, how are you so good at these ?

8. anonymous

Its all practice, I suggest you don't ask other people and actually spend at least 5 or 10 minutes trying to figure it out. You get better as you do more

9. anonymous

i do try them all out before asking but i ALWAYS get stuck :S