#include <stdio.h>

 #include <math.h>

 /*计算一元二次方程的根*/

 void Cal(double a,double b,double c);//函数申明  类似于 ax*x+bx+c=0

 int main()

 {

     double a1,b1,c1;

     printf("请输入三个参数:\n");

     scanf("%lf %lf %lf",&a1,&b1,&c1);

     Cal(a1,b1,c1);

     return ;

 }

 void Cal(double a,double b,double c)

 {

     double disc,p,q,x1,x2;

     disc=b*b-*a*c;

     if(disc<)

     {

     printf("数据校验出错");

     }else

     {

      p=-b/a*2.0;

      q=sqrt(disc)/a*2.0;

      x1=p+q;

      x2=p-q;

     }

     printf("x1的值是 %lf\n",x1);

     printf("x2的值是 %lf\n",x2);

 }