Cuadraticas con raices complejas

#include<iostream>
#include <cmath>

using namespace std;

class cuadratica{
    public:
    cuadratica( double a,double b,double c);
    void raiz ()const;

    private:
    double discriminante()const ;
    float a,b,c;
};
cuadratica::cuadratica (double a,double b,double c): a(a),b(b),c(c) {};

void cuadratica::raiz()const{

    if (discriminante()<0){//Raices complejas
        cout <<-b/(2*a) <<"+"<<sqrt(abs(discriminante()))/(2*a)<<"i ,"
             <<-b/(2*a) <<"-"<<sqrt(abs(discriminante()))/(2*a)<<"i "<<endl;
    }else {//Raices reales
        cout <<-(b+sqrt(discriminante()))/(2*a)<<","
             <<-(b-sqrt(discriminante()))/(2*a)<<endl;
    }
}

double cuadratica::discriminante ()const{return ( b*b-4*a*c);}

int main() {

    cuadratica eqReal(1,2,-8);//x^2+2x-8 raices 2 y -4 discriminante 36
    cuadratica eqImaginaria(1,-2,2);//imaginaria 1+1i , 1-1i
    cuadratica eqImaginaria2(1.5,-2.2,2.3);//imaginaria 0.733333+0.997775i ,0.733333-0.997775i

    eqReal.raiz();
    eqImaginaria.raiz();
    eqImaginaria2.raiz();

    return 0;

}