各位大6为什么运行输入数以后结果不对
#include<stdio.h>
#include<math.h>
double t ;
int main()
{
double a, b, c;
scanf_s("%f,%f,%f", &a, &b, &c);
t =(b * b) - (4 * a * c);
double geng(double a, double b, double c);
geng(a, b, c);
return 0;
}
double geng(double a, double b, double c)
{
double x1, x2,x;
if ( t > 0)
{
x1 = ( - b + sqrt(t))/(2 * a);
x2 = (-b - sqrt(t)) / (2 * a);
printf("函数的根为x1=%f,x2=%f", x1, x2);
}
else if (t == 0)
{
x = (-b + sqrt(t)) / (2 * a);
printf("函数的根为x1=x2=%f", x);
}
else {
printf("此函数无解");
}
}