Найти корень квадратного уравнения

#include<iostream.h>
#include<conio.h>
#include<math.h>
int main(){
clrscr();
int a,b,c;
cout<<"Vvedit' a,b,c:\n";
float d,D;
d=(b*b)-4*a*c;
D=sqrt(d);
if((c<0)&&(a!=0)) cout<<"Vvedayne kvadratne rivnyannay"<<a<<'x-'<<b<<'x+'<<c<<":\n";
cout<<"D="<<D;
getch();
return 0;
}

#include <iostream>
#include <math.h>
 
using namespace std;
 
int main( void ) {
 
double a,b,c;
double d, x1, x2;
 
cout <<"a*x*x+b*x+c=0. Enter a,b,c: ";
cin >>a >>b >>c;
cout <<"a=" <<a <<" b=" <<b <<" c=" <<c <<"\n";
 
if ( a == 0.0 ) {
    cout <<"Not root equation !\n";
    return 2;
}
 
d= b*b-4*a*c;
cout <<"d=" <<d <<"\n";
if ( d>0 ) {
    x1= (-b+sqrt(d))/(2*a);
    x2= (-b-sqrt(d))/(2*a);
    cout <<"x1=" <<x1 <<" x2=" <<x2 <<"\n";
} else if ( d == 0.0 ) {
    x1= (-b/(2*a)); x2= x1;
    cout <<"x=" <<x1 <<"\n";
} else {
    cout <<"equation roots not found\n";
}
 
} // main()

#include<iostream.h>
#include<conio.h>
#include<math.h>
int main(){
clrscr();
int a,b,c;
cout<<"Vvedit' a,b,c:\n";
cin>>a>>b>>c;
float D,d;
d=(b*b)-4*a*c;
D=sqrt(d);
if((c<0)&&(a!=0)) cout<<"Vvedayne kvadratne rivnyannay "<<a<<"(x*x)-"<<b<<"x+"<<c<<":";
cout<<"d="<<d<<"\nD="<<D;
getch();
return 0;
}

if ( d>0.0 ) {
        x1= (-b+sqrt(d))/(2*a);
        x2= (-b-sqrt(d))/(2*a);
        cout <<"x1=" <<x1 <<" x2=" <<x2 <<"\n";
}
if ( d == 0.0 ) {
        x1= (-b/(2*a)); x2= x1;
        cout <<"x=" <<x1 <<"\n";
}
if ( d<0.0 ) {
        cout <<"equation roots not found\n";
}

if ( d>0 ) {
        x1= (-b+sqrt(d))/(2*a);
        x2= (-b-sqrt(d))/(2*a);
        cout <<"x1=" <<x1 <<" x2=" <<x2 <<"\n";
} 
if ( d == 0.0 ) {
        x1= (-b/(2*a)); x2= x1;
        cout <<"x=" <<x1 <<"\n";
} 
if (d < 0.0){
        cout <<"equation roots not found\n";
}

#include <iostream.h>
#include <math>
void main()
  {
  const float pi=3.14;
  float va, vb, vc;
  cout << " Enter a value in 1 not quadrupeds: \n";
    cin >> va;
  cout << " Enter a value in 2 not quadrupeds: \n";
    cin >> vb;
  cout << " Enter a value in 3 not quadrupeds: \n";
    cin >> vc;
  float x1, x2;
  x1 = 2*vc/(-vb-sqrt(sqr(vb)-4*va*vc));
  x2 = 2*vc/(-vb+sqrt(sqr(vb)-4*va*vc));
  cout << "\n x1, x2 = " << x1 << ", " << x2;
  }