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Derivatives of exponential functions

  1. Apr 17, 2008 #1
    1. The problem statement, all variables and given/known data

    find the equation of the tangent to the curve defined by y=e^x that is perpendicular to the line defined by 3x+y=1

    2. Relevant equations

    m= 1/3 (negative reciprocal of y=-3x+1)
    derivative of e^x=e^x

    3. The attempt at a solution

    i keep getting stuck at 1/3=e^x ( i know theres a way to solve for x i just cant remember)

    the answer is x-3y+(1+ln3)=0
  2. jcsd
  3. Apr 17, 2008 #2
    ln(e^x) = x. You can take the natural log of both sides of an equation.
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