Work

#include <iostream>
    #include <math.h>
    using namespace std;

    double f1(double c)
    {
         return(c-(c*c-5)/(2*c)); //f1(x) = x - f(x)/f'(x)
    }

    int main()
    {
         int j=0;
         double a,b,E,x,z;
         cout<<"                    !<Course work. Teacher: Pijov Y.V.>! "<<endl<<endl;
         cout<<"                  !<Author: Yefimov D.R. @ OCCTOEU 2012>! "<<endl<<endl;
         cout<<"            <NOTE: program for solving an equation by simple iterations.> "<<endl<<endl;
         while(j!=2)
         {

             int n=0;
             cout<<"<Info>: The root must be on the interval between -A- and -B-"<<endl;
             cout<<"<Step #1>: ENTER the value -A- (for example: 2): ";
             cin>>a;
             cout<<"<Step #2>: ENTER the value -B- (for example: 3): ";
             cin>>b;
             cout<<"<Step #3>: ENTER the value -EPSILON- (for example: 0.01): ";
             cin>>E;

             x=(a+b)/2;
             do
             {
                 cout<<"Step "<<n+1<<": "<<x<<endl; //âûâîä çíà÷åíèé íà èòåðàöèÿõ, åñëè íóæíî
                 z=x;
                 x=f1(x);
                 n++;

             }
             while ((fabs(x-z))>=E);

             cout<<endl;
             cout<<"                    !CALCULATION PROCESS IS -COMPLETED-! "<<endl<<endl;
             cout<<"      <Results>: "<<endl;
             cout<<"Value -X- equals: "<<x<<endl;
             cout<<"Number of -STEPS- equals: "<<n<<endl<<endl;
             cout<<"Continue or not? (1 - YES; 2 - NO): ";
             cin>>j;
      }
    }