does anybody know how to do trig?

Question

chase · Answer

sin3x=3sinx??

anonymous · Answer

sin3x = sin(2x+x)
use sin(a+b) formula.

chase · Answer

what do you do with it from this point?
sin2xcosx+cos2xsinx=3sinx

anonymous · Answer

sin2x = sin(x+x) and cos2x = cos (x+x)

chase · Answer

I'm sorry but I'm still stuck as what I'm supposed to do with this. I put in the trig identities but after I had cancled out things and such I ended up with sinx+cosx which I'm sure is wrong

anonymous · Answer

you are supposed to get everything in terms of sin x. then you can substitute sinx = y and solve for y in a cubic equation and substitute back into sinx to find x.

chase · Answer

so would it work if I changed sinx+cosx to sinx(1-sinx)?

anonymous · Answer

I am just giving you the outline of what you need to do. I haven't solved it myself.

chase · Answer

well your insight has been most insightful, but I am hopeless a this stuff