SOLUTION: Cos theta is -0.6 and theta is in quadrant III, find sin (1/2) theta.

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Question 449672: Cos theta is -0.6 and theta is in quadrant III, find sin (1/2) theta.
Answer by lwsshak3(11628) About Me  (Show Source):
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Cos theta is -0.6 and theta is in quadrant III, find sin (1/2) theta.
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We are working with a 6-8-10 or 3-4-5 right triangle in quadrant III where cos and sin are negative.
Using half-angle formula for sine function,
sin x/2=-sqrt((1-cos x)/2)
=-sqrt((1-3/5)/2)
=-sqrt(2/5/2)
=-√.2 (ans)