c++求一元二次方程 ax^+bx+c=0 的根 一 #include #include #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."<ESSP) { root1=(-b+sqrt(delta))/(2*a); root2=(-b-sqrt(delta))/(2*a); cout<<"This eqution has two unequalize roots:"< #include int main() { double a,b,c,rp,ip;//方程系数 double x1,x2;//方程的根 double d;//根的判别式 cout<<"input a,b,c(方程系数):"; cin>>a>>b>>c; if(a==0) cout<<"这不是二元一次方程"; else { d = b * b - 4 * a * c; if(d >= 0) { if (d==0) { x1 = -b / (2*a); cout<<"只有一个实根:"<0) { x1=(-b+sqrt(d))/(2*a); x2=(-b-sqrt(d))/(a*a); } else if(d==0) { x1=x2=(-b)/(2*a); } else { double rp = -d/(2*a); double ip = sqrt ( -d ) /(2*a); x1=rp + ip; x2=rp - ip; } } void FindRoot::Display() { if(d>0) { cout<<"x1="<
