Question 817849
If sin &#920; = 2/3 and tan &#920; < 0, what is the value of cos &#920;?
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Since sine = y/r, y = 2 and r = 3
Then x = sqrt[3^2-2^2] = sqrt(5)
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Note:: if sin(t) is positive and tan(t) is negative, 
t is in QII where x is negative and y is positive.
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Therefore cos(t) = x/r = -sqrt(5)/3
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Cheers,
Stan H.
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