Question

establish the identity:

cos(3x)-cos(x)/ sin(3x)-sin(x)=-tan(2x)

can anyone help me with this?

Answer 1

Ok do you know the formula for cos3x and sin3x

Answer 2

well sorry no need for that

Answer 3

do you know the formula for cosa-cosb and sina-sinb

Answer 4

google those even u don't remember them when your done then just apply the formula in numerator and denominator

Answer 5

i mean even i don't remember them

Answer 6

as soon you apply them you will get your answer

Answer 7

You guys rock! I applied the sum to product formulas and it works. I have a final today and you guys really helped me out! Thanks for your help!