Question

What is the missing step in the proof of identity? (Picture Included/Multiple Choice)

Answer 1

A.2 sin(2theta)cos theta/-2sin(2 theta)sin(theta) B.2sin(2theta)cos theta/-2sin(2 theta)sin(-theta) C.2 sin(2 theta)cos theta/2sin(-2 theta)sin(theta) D.-2sin(2 theta)cos theta/2sin(2theta)sin(theta

Answer 2

@surjithayer

Answer 3

\[\frac{ \sin 3 \theta+\sin \theta }{ \cos \theta-\cos 3 \theta }=\frac{ 2\sin \frac{ 3 \theta+\theta }{ 2 }\cos \frac{ 3\theta-\theta }{ 2 } }{ 2\sin \frac{ \theta+3\theta }{ 2 }\sin \frac{ 3\theta-\theta }{ 2 } }\]
\[=\frac{ \sin 2\theta \cos \theta }{ \sin 2\theta \sin \theta }=?\]

Answer 4

Is the answer A then?

Answer 5

@loser66

Answer 6

I think it is b

Answer 7

B is correct.