clc
clear all
z = -2:0.01:2;
plot(z,f(z)); grid on;
x = (0);
z = (-1.5);
y = zeros();
count = 0;
for i = 1:100
   x = [x,fix(x(i))];
   disp(x(i)); format longg;
   z = [z,newton(z(i))];
   disp(z(i));
   errorx = abs(x(i) - x(1));
   errorz = abs(z(i) - z(1));

end

function fi = fix(x)
    fi = (-exp(-x) + 2*x^3)/5;
end
function fun = f(x)
    fun = exp(-x) -2.*x.^3 + 5.*x;
end

function der = deriv(x)
    der = -exp(-x) -6.*x.^2 + 5;
end

function new = newton(x)
    new = x - (f(x)/deriv(x));
end