using System;
class Example
{ public static double f(double x) { return 2-x*x;} 
  public static void Main()
  { double l=-3, r=2, eps=0.0000001, m1,m2;
    while ((r-l)>eps)
    { m1= l+(r-l)/3;
      m2=r-(r-l)/3;
      if (f(m1)<f(m2)) l=m1;
      else             r=m2;
    }
    Console.WriteLine(" f({0}) = {1} ", (l+r)/2, f((l+r)/2));
  }
}