【c语言求解】【编程入门】自定义函数求一元二次方程

解题思路:

注意事项:

参考代码:

#include<stdio.h>

#include<math.h>

int main(){

double over(double a,double b,double c);

double below(double a,double b,double c);

double a,b,c;

scanf("%lf%lf%lf",&a,&b,&c);

double del=b*b-4*a*c;

if(del>=0)over(a,b,c);

else below(a,b,c);

}

double over(double a,double b,double c){

double del=sqrt(b*b-4*a*c);

printf("x1=%.3lf x2=%.3lf",(-b+del)/(2*a),(-b-del)/(2*a));//大于等于0都可以调用这个函数

}

double below(double a,double b,double c){

double del=sqrt((4*a*c-b*b)/(4*a*a));

printf("x1=%.3lf+%.3lfi x2=%.3lf-%.3lfi",-b/(2*a),del,-b/(2*a),del);

}