function root = newton ( f, df, x )

FATOL = 0.000001;

fx = feval ( f, x ); 
format long

while ( abs ( fx ) > FATOL )

  fp = feval ( df, x );

  x = x - fx / fp;

  fx = feval ( f, x );

  [ x, fx ]

  pause

end

root = x;
