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Mystic healer
Lv 4
Mystic healer asked in Science & MathematicsMathematics · 8 years ago

can u help for that Quadratic problem?

The line y = 3x + k, is a tangent to the curve x^2 + xy + 16

find the possible values of k.

Thanks

p.s. x^2 means x square

2 Answers

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  • Your Answer
    Lv 6
    8 years ago
    Favourite answer

    The line y = 3x + k, is a tangent to the curve x^2 + xy + 16 = 0, hence

    equation x^2 + x(3x + k) + 16 = 0 will have identical roots, whence

    (3k)^2 -- 4*4*16 = 0 giving k^2 = 16^2/3^2 OR k = +/-- 16/3 ANSWER

  • mohammed
    8 years ago

    Substitute y=3x+k and find roots using delta=0

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