SOLUTION: If cos theta = -8/9 and theta is in quadrant 3 find sin theta

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Question 1009075: If cos theta = -8/9 and theta is in quadrant 3 find sin theta
Found 2 solutions by Alan3354, stanbon:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
If cos theta = -8/9 and theta is in quadrant 3 find sin theta
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sin%28t%29+=+sqrt%281-cos%5E2%28t%29%29
sine is negative in Q3

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
If cos theta = -8/9 and theta is in quadrant 3 find sin theta
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In QIII both x and y a re negative.
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By definition cos(t) = x/r.
So x = -8 and r = 9
Then y = -sqrt[9^2-8^2] = -sqrt(17)
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Ans: sin(t) = y/r = -sqrt(17)/9
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Cheers,
Stan H.
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