Answer:
sin 2theta/2
Explanation:
(1-sin^ 2 theta)(tan theta)
Recall in trig identity that
sin^2 theta + cos^2 theta = 1
cos^2 theta = 1-sin^ 2 theta
Also tan theta = sin theta/cos theta
Substitute
(1-sin^ 2 theta)(tan theta)
=cos^2 theta * sin theta/cos theta
= costheta sin theta
Since sin2 theta = 2sintheta cos theta
sintheta cos theta = sin 2theta/2