Results 1 to 3 of 3

Math Help - the derivative at a point

  1. #1
    Banned
    Joined
    Aug 2007
    Posts
    52

    the derivative at a point

    i need some help on estimating a value...the problem is

    suppose that f(x) is a function with f(380)=16 and f`(380)=8, then it says to estimate f(383)
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Newbie
    Joined
    Sep 2007
    Posts
    4
    They give you f(380)=16, a.k.a. they've given you a point (x,y). They also give you f'(380)=8, so you know the slope of the tangent at that point.

    Since we're estimating, you have three points and the slope, which give you enough information to estimate the fourth point.

    (y1-y2)/(x1-x2) = m

    Plug in and solve for the y value which is f(383).

    At least, I think that's what they want you to do.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,605
    Thanks
    1574
    Awards
    1
    Here is a general approximation: f\left( {x + \Delta x} \right) \approx f(x) + \left( {\Delta x} \right)f'(x).
    Thus, f(383) \approx f(380) + \left( 3 \right)f'(380).
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Derivative of specific point
    Posted in the Calculus Forum
    Replies: 4
    Last Post: September 13th 2011, 06:30 PM
  2. What is the derivative of f(x) at this point?
    Posted in the Calculus Forum
    Replies: 1
    Last Post: February 22nd 2010, 01:43 PM
  3. Derivative value and point finding
    Posted in the Calculus Forum
    Replies: 3
    Last Post: May 30th 2009, 02:43 AM
  4. second derivative/point of inflection
    Posted in the Calculus Forum
    Replies: 3
    Last Post: March 30th 2009, 07:53 PM
  5. Given Derivative Thru a Point
    Posted in the Calculus Forum
    Replies: 3
    Last Post: December 8th 2007, 03:50 PM

Search Tags


/mathhelpforum @mathhelpforum