C++练习题2：求方程ax2+bx+c=0的根

// stdycpp02.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
//求方程ax2+bx+c=0的根
/*方法1：用if判断求解方程的解；
*/

 1 #include <iostream>
 2 #include<cmath>
 3 using namespace std;
 4 
 5 void func_x2() {
 6     double a, b, c, d, x1, x2;
 7     cout << "求方程ax2+bx+c=0的根" << endl;
 8     cout << "请输入一元二次方程a,b,c对应的值：" << endl;
 9     cin >> a >> b >> c;
10     cout << "a=" << a << ",b=" << b << ",c=" << c << endl;
11     if (a == 0 && b == 0) {
12         cout << "方程无解" << endl;
13         return ;
14     }
15     if (a == 0) {
16         cout << "x的值是" << -c / b << endl;
17         return ;
18     }
19     d = b * b - 4 * a * c;
20     if (d < 0)
21     {
22         cout << "方程无解" << endl;
23         return ;
24     }
25     if (d == 0) {
26         x1 = (-b) / (2 * a);
27         cout << "x1=x2=" << x1 << endl;
28         return ;
29     }
30     if (d > 0) {
31         x1 = (-b + sqrt(d)) / (2 * a);
32         x2 = (-b - sqrt(d)) / (2 * a);
33         cout << "x1=" << x1 << ",x2=" << x2 << endl;
34         return ;
35     }
36 }
37 
38 int main()
39 {
40 
41     func_x2();
42 
43  //   std::cout << "Hello World!\n";
44 }

 

posted @ 2022-09-06 19:11  hanabc12345  阅读(838)  评论(0)    收藏  举报