C++代码

#include<bits/stdc++.h>
using namespace std;
int main(){
    double a,b,c;
    cin>>a>>b>>c;
    if(b*b<4*a*c||a==0.0){
        printf("Impossivel calcular\n");
    }else{
        printf("R1 = %.5lf\n",(-b+sqrt(b*b-4*a*c))/(2*a));
        printf("R2 = %.5lf\n",(-b-sqrt(b*b-4*a*c))/(2*a));
    }
    //1.在什么情况下判定方程无解 (b*b−4*a*c)<0
    //2.R1=??? 第一种:+ (-b+sqrt(b*b-4*a*c))/(2*a)
    //3.R2=??? 第二种:- (-b-sqrt(b*b-4*a*c))/(2*a)
    return 0;
}