#include "head.h"
 
int main(void)	
{
 
double guess, root;	//variables needed for Newton.
char choice = 81;  // 81 is decimal code for capital Q; 113 is lower case q
int enterkey, i;
do {
 
cout << "\nmenu displayed:  Enter A for 6.a., B for 3., or Q to quit ";
 
 
    	cout << "\nFor example, type B for Exercise 3 followed by Enter key  ";
    	choice = toupper(getchar( ));  enterkey = getchar( );
   	 cout << choice <<":"<< enterkey << endl;
switch (choice)	// a decision structure to select only one case out of many
{
 
 
 
case 'A':	
	for(i=1;i<=2;i++)
	{
	cout<<"Enter a negative followed by a positive "<<endl;
	cin>>guess;
	cout<<"Call Newton(given guess), returns and saves root\n";	
	cout<<"After Newton the root is "<<Newton(guess)<<endl;
	}//end for
	cout<<"After the loop i is  "<<i<<endl;
	break;
default:
if (choice != 'Q')	
{cout << "\nIncorrect Choice: Enter (A,B, or Q as valid)\n";
}//endif
} //  end switch
 
} while (choice != 'Q');  //end do-while
 
cout << " Fini\n";
 
 
system("pause");
return 0;

double guess, xi,root;
int i;
double Newton(double guess)
	{		
	for (i=1,10;1;)
	{
	xi=guess;
	(xi)=(xi-(3*pow(xi,2)+2*xi-2)/(6*xi+2));
	}//end for
	root =xi;	
	cout<<"in Newton\n";
		return root;
	}