Posted by **ALISON** on Sunday, October 23, 2011 at 5:34pm.

Verify the following identity.

1) sin(x+y)

__________ = tanx+tany

cosxcosy

2) Write cos3x in terms of cosx

I cannot figure out how to solve for identities they are so hard. Any help appreciated!:)

## Answer this Question

## Related Questions

Math (trigonometry) - Trigonometry identities are so hard... I need some help ...

Trig - Verify that each of the following is an identity. tan^2x-sin^2x=tan^2xsin...

Precalculus/Trig - I can't seem to prove these trig identities and would really ...

Pre-Cal (verifying trig identities) - How would you verify the identity? sin^1/...

trig - verify the identity (tanx+cotx) (1) __________ = ______________ (tanx-...

precalculus - 1.csc^2x-1/csc^2x=cos^2x 2.1/1-cosx+1/1+cosx=2csc^2x 3.sinxcosy+...

Simplifying with Trigonometry Identities - Hi, I am a senior in High School ...

Math, please help - Which of the following are trigonometric identities? (Can be...

trig - it says to verify the following identity, working only on one side: cotx+...

Mathematics - Trigonometric Identities - Prove: (tanx)(sinx) / (tanx) + (sinx...