Question 100849
Suppose that sec(2t)=(-13/12), and that pi/2<t<0.
Find the exact value of cos(t)
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sec(2t)=(-13/12)
cos(2t)=(-12/13)
2t = cos^-1(-12/13) = 157.38 degrees
t = 78.69 degrees
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Cheers,
Stan H.