Counting the roots of quadratic equation using the function class

class in c + + function to categorize the variables, class is almost the same as the struct, the difference is the class name can be changed while in stuctr can not.

Counting the roots of quadratic equation programs use the function class
#include
#include
#include
class Persamaan{
public:
Persamaan();
void hitung();
private:
double a,b,c;
double diskriminan,x1,x2,re,im;
};
int main()

{

Persamaan x;
x.hitung();
getch();
return 0;
}
Persamaan::Persamaan(){
cout << "Persamaan Kuadrat" << endl;
cout << "a : ";

cin >> a;
cout << "b : ";

cin >> b;
cout << "c : ";

cin >> c;
}
void Persamaan::hitung (){
// hitung diskriminan
diskriminan=b*b-4*a*c;
if(diskriminan > 0)
{
x1 = (-b + sqrt(diskriminan))/(2*a);
x2 = (-b - sqrt(diskriminan))/(2*a);
cout << "Akar real : " << endl;
cout << "x1 : " << x1 << endl;
cout << "x2 : " << x2 << endl;

}
else
if(diskriminan ==0)
{
x1=-b/(2*a);
x2=x1;
cout << "Akar kembar : " << endl;

cout << "x1 : " << x1 << endl;

cout << "x2 : " << x2 << endl;

}
else //diskriminan <0
{
re= -b/(2*a);
im= sqrt(fabs(diskriminan))/(2*a);
cout << "Akar kompleks : " << endl;
cout << "x1 : " << re <<" + " << im << endl;
cout << "x2 : " << re <<" - " << im << endl;

}
}