C++二次方程求解器 - 不正确的虚解

正如标题所说，每当我在二次方程求解器中输入某些数字导致虚解时，我都无法表达正确的虚解。

我尝试的一些事情包括创建一个新的强制转换变量，它基本上是判别式的绝对值，但作为一个全新的变量。

此外，我尝试使用判别变量本身，包括 abs(( 函数和绝对值的负乘以。

我感谢任何意见。 如果你们需要它，这是我的代码。

编辑：如果您想知道我输入的一些值，我输入了 2、-5 和 4 作为 A、B 和 C。 如果要检查计算器/二次求解器，该值约为 1.25 +- 0.66I，但我得到 3.00*I 和 -0.5*I。

#include <iostream>
#include <cmath>
#include <string>
#include <iomanip>
using namespace std;
int main() {
cout << fixed << scientific << setprecision(5);
cout << setfill('*') << setw(61) << '*' << endl;
cout << "5Chan Christina Quadratic Equation Solver" << endl;
cout << setfill('*') << setw(61) << '*' << endl;
cout<< "Welcome to Quadratic Equation Solver, where we will input solutions from your inputs based on the form" << endl;
cout << setw(31) << "Ax^2 + Bx + C = 0" << endl;
cout << "Where A, B, and C are integers, and A is not equal to zero." << endl;
cout << setfill('*') << setw(61) << '*' << endl;
int A, B, C;

// discriminant program

// The following equations represent both
//parts of the quadratic equation, converted to double form

cout << "Enter the input for A. " << endl;
cin >> A;
if (A == 0)
/* Here, when A == 0
The following statements are executed under such subconditions
*/
{
cout << "Warning, any more 0 input will not produce any equation!" << endl;
cout << "Enter the input for B. " << endl;
cin >> B;
if (B == 0)
{
cout << "Invalid! Start over! You do not have an algebraic equation!" << endl;
cout << setfill('*') << setw(61) << '*' << endl;
cout << "Thank you for using Quadratic Equation Solver!" << endl;
cout << setfill('*') << setw(61) << '*' << endl;
}
// tfw your input results in a linear equation...
else if (B != 0)
{
cout << "Enter the input for C. " << endl;
cin >> C;
double lin_eq = static_cast<double>(-C)/B; 
// linear equation form when b is NOT 0
cout << "Solution is " << endl;
cout << setw(50) << lin_eq << endl;
cout << setfill('*') << setw(61) << '*' << endl;
cout << "Thank you for using Quadratic Equation Solver!" << endl;
cout << setfill('*') << setw(61) << '*' << endl;
}
}
else //basically, when A is NOT zero
{
cout << "Enter the input for B. " << endl;
cin >> B;   
cout << "Enter the input for C. " << endl;
cin >> C;
double disc = static_cast<double>((B*B)-(4*A*C));
double quad_1 = static_cast<double>((-B) + sqrt((B*B) - (4*A*C)))/(2*A);
double quad_2 = static_cast<double>((-B) - sqrt((B*B) - (4*A*C)))/(2*A);

if (disc > 0) // discriminant greater than 0
// 2 solutions are printed 
{
cout << "The two real solutions are" << setw(31) << quad_1 << endl;
cout << setw(20) << "and" << setw(51) << quad_2;
cout << setfill('*') << setw(61) << '*' << endl;
cout << "Thank you for using Quadratic Equation Solver!" << endl;
cout << setfill('*') << setw(61) << '*' << endl;
}
else if (disc == 0) 
{
cout << "Solution is " << endl;
cout << setw(50) << quad_2 << endl;
cout << setfill('*') << setw(61) << '*' << endl;
cout << "Thank you for using 5Chan Christina Quadratic Equation Solver!" << endl;
cout << setfill('*') << setw(61) << '*' << endl;

}       
else if (disc < 0) // This segment of code 
// Prints imaginary values through discriminant abs value
{
double imag_help =  static_cast<double>(abs(disc));
double imag_solution_1 = ((-B+imag_help)/(2*A));
double imag_solution_2 = ((-B-imag_help)/(2*A));
cout << "The two imaginary solutions ARE" << setw(31) << "x= " << imag_solution_1 << "*I" << endl;
cout<< setw(15) << " AND "  << setw(31) << "x=" << imag_solution_2 << "*I" << endl;
cout << setfill('*') << setw(61) << endl;
cout << "Thank you for using Quadratic Equation Solver." << endl;
cout << setfill('*') << setw(61) << endl;


}


}

}