一个关于Ｃ语言的问题

Question

用户输入一元二次方程ax^2+bx+c=0的系数a b c. 编写程序判断该方程在实数范围内是否有根并输出其实数根.

Answer 1

#include <stdio.h>
#include <math.h>
int main()
{
    double disc, a, b, c, p, q, x1, x2;
    printf("请输入a和b和c的值：\n");
    scanf("%lf %lf %lf", &a, &b, &c);
    disc = b * b - 4 * a * c;
    if (disc < 0)
        printf("改方程无实数根\n");
    else
    {
        p = (-b) / (2 * a);
        q = sqrt(disc) / (2 * a);
        x1 = p + q;
        x2 = p - q;
        printf("x1=%7.2f\nx2=%7.2f\n", x1, x2);
    }
    return 0;
}