%var u
parametric_plot3d( (sin(u), cos(u), u/10), (u, 0, 20), thickness=5, color='green', plot_points=100)
x = var('x');             # declare the variable for function
f(x)=x^2-2;               # change this to whatever function you like
#f(x)=x^3
#f(x)=x/(1+x^2)
df=diff(f,x);             # Store the Derivative of f
Newton(x)=x-(f/df)(x);    # Newtons Iterative Formula (simply called Newton)
plot(f,[-5,5])

xn=2.0;
xn;
Newton(xn)

xn=400
xs=[xn]
n=10
for i in [1..n]:
    xn=N(Newton(xn),digits=20)
    xs.append(xn)
    print xn;
    
print xn