Question 641829: if csc(theta)=13/5 and theta is in the second quadrant, what is sec(theta)? I have no clue how to do this, can you please help?
Thank you very much!
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! if csc(theta)=13/5 and theta is in the second quadrant, what is sec(theta)?
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csc(theta) = r/y, so r = 13 and y = 5
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Solve for "x":
x = sqrt[r^2-y^2] = sqrt(13^2-5^2] = sqrt[169-25] = sqrt(144) = 12
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But x is negative in the sesond quadrant, so x = -12
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Ans: sec(theta) = r/x = 13/(-12) = -13/12
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Cheers,
Stan H.
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