C语言 解方程。。大家帮忙看看这个程序吧~~

#include#include main(){float a,b,c,d,x,y,x1,x2;printf("Please input three float numbers:");scanf("%f%f%f",&a,&b,&c);if(a==0) { printf("The equation is not quadratic."); }else { d=b*b-4*a*c; if(d==0)//改成==