MATLAB: This is a question from numerical methods asking to explain what the code does for 12 marks.

Question

% function [func,deriv]= fcn_nr(x)
%   func = x^4 - 5*x^3 -124*x^2 + 380*x + 1200;
%   deriv = 4*x^3 -15*x^2 -248*x +380;
x = input('Enter initial guess of root location:');
itermax = 100;
iter =0;
errmax =0.001;
error = 1;
fprintf('\n #root rel error\n\n');
while error > errmax & iter <itermax
    
    iter = iter+1;
    [f fprime] = fcn_nr(x);
    x=x-f/fprime
    if fprime ==0
        fprintf('ERROR:deriv(x)=0;can"t divide by zero\n')
        break;
    end;
end

Answer 1

https://en.wikipedia.org/wiki/Newton%27s_method