Question
Prove that tan4x=4tanx(1-tan²x)/1-6tan²x+tan⁴x.
Answers
Steve
I think the best way to start would be
tan 4x = 2*tan 2x/(1-tan^2 2x)
= 2(2tanx/(1-tan^2x)) / (1-(2tanx/(1-tan^2x))^2)
Now place top and bottom over a common denominator of (1-tan^2x)^2
and you should see things going where you want them.
tan 4x = 2*tan 2x/(1-tan^2 2x)
= 2(2tanx/(1-tan^2x)) / (1-(2tanx/(1-tan^2x))^2)
Now place top and bottom over a common denominator of (1-tan^2x)^2
and you should see things going where you want them.