How do you simplify sin2theta -tan2theta using the double angle identities?

1 Answer
Jul 25, 2016

sin2theta-tan2theta

=(2tantheta)/(1+tan^2theta)-(2tantheta)/(1-tan^2theta)

=(2tantheta(1-tan^2theta-1-tan^2theta))/((1+tan^2theta) (1-tan^2theta))

=(-2tantheta(2tan^2theta))/((1+tan^2theta)(1-tan^2theta))

=-(4tan^3theta)/((1+tan^2theta)(1-tan^2theta))

=(4tan^3theta)/(tan^4theta-1)