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Homework Help: Find points on curve with a tangent line

  1. Feb 10, 2010 #1
    1. The problem statement, all variables and given/known data
    Find points on curve y=sinhx where the tangent line has slope 2



    2. Relevant equations



    3. The attempt at a solution
    y' = 1/(sqrt(1-x^2)) = 2
    4 = 1/(1-x^2)
    4-4x^2=1
    x=sqrt(3/4)

    the actual answer should be x = +or- ln(2+sqrt(3))
     
  2. jcsd
  3. Feb 11, 2010 #2

    rock.freak667

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    Homework Helper

    d/dx(sinhx)=coshx = (ex+e-x)/2

    then solve for ex
     
  4. Feb 11, 2010 #3
    Remember that the derivative of arcsin x or sin-1x = 1/√(1 - x2). sinh is the hyperbolic sine.
     
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