trig
posted by Josh on .
TRIG Identities, Gr. 12:
Prove:
cot4x=1tan^2x/2tan2x

just apply the doubleangle formula for tan(2x) and take the reciprocal

okay, thank you, would that still apply if it was cot4x=1tan^2(2x)/2tan2x? because ive got the right side for this one but the cot4x is throwing me off, how would you solve that side?

you are exactly right
tan(4x) = 2tan2x/(1tan^2(2x))
so, cot(4x) is the reciprocal, as needed.