SOLUTION: Given tan(theta)=-4/5 and cos(theta)>0, find the exact values of sin(theta) and sec(theta).

Question 841416: Given tan(theta)=-4/5 and cos(theta)>0, find the exact values of sin(theta) and sec(theta).
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Given tan(theta)=-4/5 and cos(theta)>0, find the exact values of sin(theta) and sec(theta).
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Since tan is negative and cos is positive, theta is in QIV where
x is positive and y is negative.
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tan = y/x = -4/5 implies x = 5 and y = -4
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Then r = sqrt[5^2+4^2] = sqrt(41)
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Your Problem:
sin(t) = y/r = -4/sqrt(41)
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sec(t) = r/x = sqrt(41)/5
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Cheers,
Stan H.
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