function [x]=hw2_1_12()

% Iteratively solve the equation x^2-x-1=0 (using Newton's method)
oldx=2;    % initial geuss for x
x=1+1/oldx;

% iterate while the tolerance condition on x is NOT true
while(abs(x-oldx)>0.0005)
    oldx=x;     % remember the previous value of x then ...
    x=1+1/oldx; % ... update the value
end

disp('check the answer (should be close to 0)')
disp(x^2-x-1)