Question

if 2tanx/1-tan^2x=1, then x can equal

There can be more than 1 answer

a) x=5pi/8 + npi
b) x=pi/8 + npi
c) x=3pi/8 + npi
d) x=7pi/8 + npi

Answer 1

hey,
what have you tried?

if you take tan x as y
you'll get a quadratic in y

Answer 2

or you can also use the formula of tan(A+B) and realize that the left side is just
\(\Large \tan 2x\)