Question

prove identity using sum or difference identity tan 2u= (2 tanu)/1-tan^2 u

Answer 1

start with sin (2u)/cos (2u) and work from there

Answer 2

on the tan 2u side?

Answer 3

yes

Answer 4

andddd im stuck ;/

Answer 5

sin (2u) => 2 sin u cos u
I can't remember what cos 2u goes to, but you should be able to find out fairly quickly