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If sin θ = 5/13 and θ is acute, what is the value of cos θ?
A12/13
B5/12
C13/12
D8/13
Answer & Solution
Correct answer: A. 12/13
Since sin²θ + cos²θ = 1, cos²θ = 1 - 25/169 = 144/169, so cos θ = 12/13 for an acute angle.
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