SOURCE FILE: quadrat_v2.cpp

/*
    This is a program to solve a quadratic equation like 5X^2 + 6X + 1 = 0.
*/

#include <iostream>
#include <cmath>

using namespace std;

int main (void)
{
   double x1, x2 ;
   double discr ;
   double sqrtDiscr ;
   double  a, b, c ;

   cout << endl ; // Start this set of  outputs with a blank line

   cout << "Please enter a real number for coefficient a: " ;
   cin >> a ;
   cout << "Please enter a real number for coefficient b: " ;
   cin >> b ;
   cout << "Please enter a real number for coefficient c: " ;
   cin >> c ;

   discr = b*b - 4*a*c ;

   cout << endl ; // Start this set of  outputs with a blank line

   if ( discr < 0 )
   {  // Do this if discr < 0
      cout << "Sorry, no real solution.\n" ;
   }
   else
   {  // Do this if discr >= 0

      if (discr == 0)
      {
           // Do this if discr ==  0
         cout << "There is only one root: " << ( -b/(2*a) ) << endl ;
      }
      else 
      {
           // Do this if discr > 0
         sqrtDiscr = sqrt(b*b - 4*a*c) ;
         x1 = (-b + sqrtDiscr) / (2*a) ;
         x2 = (-b - sqrtDiscr) / (2*a) ;
         cout << "The first root is: " << x1 << endl ;
         cout << "The second root is: " << x2 << endl ;
      }
   }
   cout << endl ; // Print a blank line at the end of everything
   return 0 ;
}