 
 
 
newton takes as arguments : an expression ex, 
the variable
name of this expression (by default x), and three values a (by 
default a=0), eps (by default eps=1e-8) and nbiter 
(by default nbiter=12).
newton(ex,x,a,eps,nbiter) computes an approximate 
solution x of the equation ex=0
using the Newton algorithm with starting point 
x=a. The maximum number of iterations is nbiter
and the precision is eps.
Input :
^2-2,x,1) Output :
Input :
^2-2,x,-1) Output :
Input :
Output :
 
 
