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Tangent to X^2

  1. Feb 9, 2010 #1
    1. The problem statement, all variables and given/known data
    For what values of k is the line y = kx - 2 tangent to the graph of f(x) = x^2?


    2. Relevant equations



    3. The attempt at a solution

    Would I just find f'(x) = 2x?
     
  2. jcsd
  3. Feb 9, 2010 #2

    rock.freak667

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    Homework Helper

    No but solving y=kx-2 and y=x2 would yield only one solution for x

    Hint: recall the condition in the quadratic equation formula for equal roots.
     
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