Question

Which expression is equivalent to (tan(theta/2))(-sin theta)

Answer 1

Explanation:

`(tan(\theta)/(2) )(-sin\theta)\\=((sin~(\theta)/(2) )/(cos(\theta)/(2) ) )(-2sin(\theta)/(2) cos(\theta)/(2))\\=-2sin ^2 (\theta)/(2) \\=cos ~2 \theta-1`