function [ x, e ] = secant1( f,l,r,n )
%Bisection_1 calculates root of function between l and r with n iterations
%   output: approximate value x, estimated error e


fl = f(l);
fr = f(r);
res = [NaN, l, r, fl, fr, r-l];

if fl*fr > 0.0
    error('Function has same sign at both initial end points l and r \n');
end

% Main loop of algorithm

for i = 1:n
    
    x = l - (r-l)/(fr-fl) *fl; 
    y = f(x);
        
    if y == 0.0 
        e = 0;
        break
    end
    
    if fl*y > 0 % Trick: check if same sign!
        l  = x;
        fl = y;
    else
        r  = x;
        fr = y;
        
    end
    
    e = (r-l)/2;   % Rough estimate for error

    res = [res; x, l, r, fl, fr, e];

end
ROWS = [0:n];
printmat(res, 'Results', num2str(ROWS), 'x l r fl fr e');
plot([0:n], log(res(:,6)));

end