SOLUTION: if sin A = 5/13 for angle A in quadrant 1, find sin A/2

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Question 974066: if sin A = 5/13 for angle A in quadrant 1, find sin A/2
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
if sin A = 5/13 for angle A in quadrant 1, find sin A/2
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sin(A/2) = sqrt[(1-cos(A))/2]
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cos(A) = sqrt[13^2-5^2]/13 = 12/13
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Ans: sin(A/2) = sqrt[(1-(12/13))/2] = sqrt[(1/13)/2] = sqrt(1/26)
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Cheers,
Stan H.
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