how can i solve nonliner equation?

I tryed to find roots of nonliner equation by use all posible codes: fsolve, fzero, fixed pointes, raphson method.

Equation is: x^2-x+1.

Help me.

[KSSV]

Show us what have you tried and why it didn't work..

[Mariam Sordia]

1. Raphson method:

clc

clear all

x0=1;

x=x0;

xold=x0;

iter=50;

round=1e-6;

for i=1:iter

f=x^2-x+1;

df=2*x-1;

x=x-f/df

err=abs(x-xold)

xold=x

if err<round

break

end

end

Answer 1

[Alan Stevens]

look at documentation on the "roots" function, (ie type help roots).

[Mariam Sordia]

roots for solve nonliner equation?

[Alan Stevens]

Your equation is a 2nd order polynomial, with coefficients o f 1, -1 and 1:

>> coeffs = [1 -1 1];

>> roots(coeffs)

ans =

0.5000 + 0.8660i

0.5000 - 0.8660i

[Alan Stevens]

Notice that the roots are complex, which is why your Newton Raphson code didn't work. Try setting x0 = 1+1i in your code.

[Mariam Sordia]

Thanks