Newton's Method for finding zeros

19 views (last 30 days)
Lucas Brockman
Lucas Brockman on 6 Feb 2019
Answered: Geoff Hayes on 7 Feb 2019
I am trying to divide the function f(x0) by its derivitive df(x0), but Matlab keeps giving me errors about dividing by df(x0). My code is the following:
clear;
syms x f(x) f df(x) df
f = @(x) x.^2 - 3;
df = diff(f,x);
x0 = 1;
N = 6;
epsilon = 0.000001;
for t = 1:N
j = x0;
x0 = x0 - f(x0)/df(x0);
end
disp(x0)

Answers (1)

Geoff Hayes
Geoff Hayes on 7 Feb 2019
Lucas - what errors are you observing? Please copy and paste the full error message to your question. Do you need to use the Symbolic Toolbox? Can't you define df as just
df = @(x)2*x;
Note how your code isn't using epsilon. How are you supposed to be using this value?

Categories

Find more on Symbolic Math Toolbox in Help Center and File Exchange

Products

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!