Python
```python
import math
def solve_quadratic(a, b, c):
discriminant = b 2 - 4 * a * c
if discriminant > 0:
root1 = (-b + math.sqrt(discriminant)) / (2 * a)
root2 = (-b - math.sqrt(discriminant)) / (2 * a)
return root1, root2
elif discriminant == 0:
root = -b / (2 * a)
return root,
else:
realPart = -b / (2 * a)
imaginaryPart = math.sqrt(-discriminant) / (2 * a)
return complex(realPart, imaginaryPart), complex(realPart, -imaginaryPart)
示例方程: x^2 + 2x - 3 = 0
a = 1
b = 2
c = -3
solution = solve_quadratic(a, b, c)
print(f"The solutions are: {solution}")
```
Java
```java
import java.util.Scanner;
public class Text {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println("请输入a:");
double a = sc.nextDouble();
System.out.println("请输入b:");
double b = sc.nextDouble();
System.out.println("请输入c:");
double c = sc.nextDouble();
double discriminant = b * b - 4 * a * c;
if (discriminant > 0) {
double x1 = (-b + Math.sqrt(discriminant)) / (2 * a);
double x2 = (-b - Math.sqrt(discriminant)) / (2 * a);
System.out.println("解: x1=" + x1 + " x2=" + x2);
} else if (discriminant == 0) {
double x = -b / (2 * a);
System.out.println("解: x1=" + x + " x2=" + x);
} else {
System.out.println("此方程无解");
}
}
}
```
C++
```cpp
include include void gt(int a, int b, int c) { double x1 = (-b + sqrt(b * b - 4 * a * c)) / (2 * a); double x2 = (-b - sqrt(b * b - 4 * a * c)) / (2 * a); std::cout << "x1=" << x1 << " x2=" << x2 << std::endl; } void eq(int a, int b, int c) { double x1 = (-b + sqrt(b * b - 4 * a * c)) / (2 * a); double x2 = (-b - sqrt(b * b - 4 * a * c)) / (2 * a); std::cout << "x1=" << x1 << " x2=" << x2 << std::endl; } void lt() { std::cout << "此方程无解" << std::endl; } int main() { int a, b, c; std::cin >> a >> b >> c; if ((b * b - 4 * a * c) > 0) { gt(a, b, c); } else if ((b * b - 4 * a * c) == 0) { eq(a, b, c); } else { lt(); } return 0; } ``` 这些代码示例分别展示了如何使用Python、Java和C++求解一元二次方程。每种语言的代码都遵循了相同的基本步骤: 1. 定义一元二次方程的系数a、b和c。 2. 计算判别式Δ(即b² - 4ac)。 3. 根据判别式的值判断方程的根的情况: 如果Δ > 0,方程有两个不同的实数根。 如果Δ = 0,方程有一个实数根(重根)。 如果Δ < 0