secant mat

function xc = secant(f, x0, x1, k)
    x(1) = x0;
    x(2) = x1;
    for i=2:(k+1)
        x(i+1) = x(i) - f(x(i))*(x(i)-x(i-1))/(f(x(i)) - f(x(i-1)));
    end
    xc = x(k + 2);
end