function x_k = secant(k)
    if k == 0
        x_k = 1;
    else if k == 1
        x_k = 1.5;
    else
        f = @(x) x^3 -2;
        x_k = secant(k-1) - (f(secant(k-1)) * ((secant(k-1) - secant(k-2))/(f(secant(k-1)) - f(secant(k-2)))));
        end
    end