Question 827226
Find x so that P(x, -√(13)/4) lies on the unit circle 
in the third quadrant, find θ.
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The radius is 1.
x is negative in the third quadrant
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Equation:
Use Pythagoras to get:
x^2 + (sqrt(13)/4)^2 = 1
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x^2 = 1-(13/16) = 3/16  
x = -sqrt(3)/4
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theta = arctan[(sqrt(13)/4)/(sqrt(3)/4)] = arctan(sqrt(13/3)) = 64.34 degrees
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Solution in QIII:: 180+64.34 = 244.34 degrees
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Cheers,
Stan H.
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