Question 398192
Suppose alpha is an acute angle and cos(alpha) = sqrt(3)/5. 
Find the exact value of 3sec^2(alpha).
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cos(alpha) = x/r, so x = sqrt(3) and r = 5
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sec(alpha) = r/x = 5/sqrt(3)
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3sec^2(alpha) = 3*(25/3) = 25
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Cheers,
Stan H.