Question

sin theta= 3/4
located in quadrant 2
what is sin2theta, cos2theta, and tan2theta.
Please help, have no clue how to even start

Answer 1

\[\sin(2 \theta) = 2 \cos \theta \sin \theta\]
\[\cos(2 \theta) = \cos^2 \theta - \sin^ 2 \theta \]
\[\tan 2 \theta = \frac{ 2 \tan \theta }{ 1- \tan ^2 \theta }\] you can use these identities