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    Question

    If x2 – 5x + 1 = 0, then find the value of

    {x2 + (1/x2)}.
    A 29 Correct Answer Incorrect Answer
    B 25 Correct Answer Incorrect Answer
    C 27 Correct Answer Incorrect Answer
    D 23 Correct Answer Incorrect Answer

    Solution

    Since, x2 – 5x + 1 = 0  So, x2 + 1 = 5x  Dividing each term by ‘x’, we get Or, x + (1/x) = 5 Squaring both sides, we get (x + 1/x)2 = 52 = 25 Or, x2 + (1/x2) + 2 = 25 Or, x2 + (1/x2) = 23   

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