Question

    If cos² x + sin x = 5/4, then find the value of 'sin x'.

    A 3/2 Correct Answer Incorrect Answer
    B –1/2 Correct Answer Incorrect Answer
    C 3/4 Correct Answer Incorrect Answer
    D 1/2 Correct Answer Incorrect Answer

    Solution

    cos² x + sin x = 5/4   (1 - sin² x + sinx) = 5/4 Let sin x =a   4a2 - 4a + 1 = 0 4a2 - 2a - 2a + 1 = 0 2 a (2a - 1) - 1 (2a - 1) = 0 (2a-1) (2a - 1) = 0 2a = 1 a = ½ Sinx =1/2

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