Results 1 to 3 of 3

Math Help - Finding roots with Newton's method

  1. #1
    Newbie
    Joined
    Dec 2008
    Posts
    2

    Finding roots with Newton's method

    How can I find three roots of F(x)=cosx+0.2x with newton's method?
    And,for all roots;I need take n(iteration number) ,but how can I identify iteration number?


    thanks so much
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by Mandelbrot View Post
    How can I find three roots of F(x)=cosx+0.2x with newton's method?
    And,for all roots;I need take n(iteration number) ,but how can I identify iteration number?


    thanks so much
    You need to find starting points close to each root, they are close to x=-1.3,\ x=2.0,\ x=3.8. Then use standard Newtons method starting from each.

    You don't normaly precompute how many itterations you need, but keep going untill |x_{n+1}-x_n| is less than some preset tolerance.

    CB
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Dec 2008
    Posts
    2
    thank u CB,I will have to study with these roots now,then I'll think about iteration..

    thank u so much
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 0
    Last Post: October 4th 2010, 12:24 AM
  2. Finding the roots through Newtons method
    Posted in the Calculus Forum
    Replies: 1
    Last Post: August 14th 2010, 07:25 AM
  3. Replies: 1
    Last Post: February 7th 2010, 09:42 AM
  4. Quickest method of finding roots....
    Posted in the Advanced Algebra Forum
    Replies: 2
    Last Post: May 18th 2009, 09:04 PM
  5. [SOLVED] Finding zeropoint with Newton's method
    Posted in the Advanced Algebra Forum
    Replies: 1
    Last Post: November 17th 2005, 09:26 AM

Search Tags


/mathhelpforum @mathhelpforum