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Tangent Line

  1. Nov 7, 2011 #1
    Hi everyone,

    Please I have a problem to find a slope (Tangent line) of any linear function without using (x2-x1; y2-y1).
    What I want is a function that can be applied in any position of any type of function, example: x2, 3x3+sin(x), ln(x)+x3, and so one. (Like as in this web page "Java Applet" : http://www.math.brown.edu/help/tangentline.html [Broken])

    Thank you.
    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Nov 7, 2011 #2


    Staff: Mentor

    Is this a homework problem?

    What you are asking is unclear. A linear function is one with the form f(x) = ax + b. This function's graph is a straight line with slope a.

    For other functions, such as the ones you mentioned, the slope of the tangent line at a point on the curve, is given by the derivative of the function, evaluated at the x value at the point in question.

    So are you asking about linear functions or functions in general?
    Last edited by a moderator: May 5, 2017
  4. Nov 8, 2011 #3
    I ask about linear function.
  5. Nov 8, 2011 #4


    User Avatar
    Science Advisor

    Any linear function of x can be written as y= ax+ b for some numbers a and b. The slope is the number a.
  6. Nov 10, 2011 #5
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