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    Question

    In a triangle △ ABC, the angle ∠ ABC = 90°. If

    sin(A) = 1/2, then cos(C) is equal to:
    A 1/√2 Correct Answer Incorrect Answer
    B 1 Correct Answer Incorrect Answer
    C √3/2 Correct Answer Incorrect Answer
    D 1/2 Correct Answer Incorrect Answer

    Solution

    In triangle △ABC, ∠ABC = 90°. So, ∠A + ∠C = 90° → ∠C = 90° − ∠A Given: sin(A) = 1/2
    ⇒ ∠A = 30° (since sin(30°) = 1/2)
    ⇒ ∠C = 60° So, cos(C) = cos(60°) = 1/2

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