Question

    If (x2 + y2) = 9 and

    (xy)2 = 3, then find the value of (x4 + y4).
    A 75 Correct Answer Incorrect Answer
    B 45 Correct Answer Incorrect Answer
    C 65 Correct Answer Incorrect Answer
    D 85 Correct Answer Incorrect Answer

    Solution

    Given, x2 + y2 = 9 Squaring both sides, we get ⇒ x4 + y4 + 2x2y2 = 81 ⇒ x4 + y4 = 81 – 6 ⇒ x4 + y4 = 75

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