问一个方程中的小问题？？？
#include <stdio.h>#include <math.h>
void main()
{
float a,b,c,disc,x1,x2,realpart,imagpart;
scanf("%f,%f,%f,%f",&a,&b,&c);
printf("The equation");
if(fabs(a) <= 1e-6)
printf("is not a quadratic\n");
else
{
disc = b*b - 4*a*c;
if(fabs(disc) <= 1e-6)
{
printf("has two equal roots: %8.4f\n", -b/(2*a));
}
else
if(disc > 1e-6)
{
x1 = (-b + sqrt(disc))/(2*a);
x2 = (-b - sqrt(disc))/(2*a);
printf("has distinct real roots: %8.4f and %8.4f\n",x1,x2);
}
else
{
realpart = -b/(2*a);
imagpart = sqrt(-disc)/(2*a);
printf("has complex roots: \n");
printf("%8.4f + %8.4fi\n",realpart,imagpart);
printf("%8.4f - %8.4fi\n",realpart,imagpart);
}
}
}
这个方程中的“1e-6”是什么意思啊？？？在数学中怎么表示的？？？
