It's trigo time #3

Geometry Level 2

Which of the following are true?

A. $tan\theta =$ $\frac{sin\theta }{cos\theta }$

B. $sin\theta \cos\theta \tan\theta =1-cos^2\theta$

C. $cos^2\theta - sin^2 \theta =1-2sin^2\theta$

This is a part of a set: It's trigo time

A only A and B A,B and C C only B and C A and C B only