Question 590941
cscx=-5/3 pi<x<3pi/2  find extact value of sinx/2,cosx/2, tanx/2
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sin(x) = 1/csc = -3/5
x is in Q3 or Q4
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{{{cos(x) = sqrt(1 - sin^2(x))}}}
cos = 4/5 in Q4 or - 4/5 in Q3
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tan = sin/cos
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Use the half-angle formulas on Wikipedia.  It's all plug-in formulas.