Question

c++求一元二次方程ax^+bx+c=0的根

刚学习,不怎么会,请大家帮帮忙,谢谢了

Answer 1

#include <iostream.h>
#include <math.h>
#define ESSP 0.00000001
void main()
{
double a,b,c,delta,root1,root2;
cout<<"Please input a:";
cin>>a;
cout<<"Please input b:";
cin>>b;
cout<<"Please input c:";
cin>>c;
delta=b*b-4*a*c;
if(delta<-ESSP)
cout<<"This equation has no real root."<<endl;
else if(delta>ESSP)
{
root1=(-b+sqrt(delta))/(2*a);
root2=(-b-sqrt(delta))/(2*a);
cout<<"This eqution has two unequalize roots:"<<root1<<root2<<endl;
}
else
{
root1=-b/(2*a);
cout<<"This eqution has two equalize roots:"<<root1<<endl;
}
}

Answer 2

很普通的问题
好多参考书上就有啊。
好像C语言教材里就有，然后用C++描述就可以了。

要用到公式。