这样定义有什么错误？？ #include<math.h> #define P (-b/2a) #define disc b*b-4*a*c #define Q (sqrt(disc)/2a)

main() { float a,b,c,x1,x2;

printf("Please input three number :"); scanf("%f,%f,%f",&a,&b,&c); x1=P+Q; x2=P-Q; printf("\n x1==%5.3f x2==%5.3f \n",x1,x2); }

main() { float a,b,c,x1,x2;

printf("Please input three number :"); scanf("%f,%f,%f",&a,&b,&c); x1=P+Q; x2=P-Q; printf("\n x1==%5.3f x2==%5.3f \n",x1,x2); }