Giai PT bac 2

// Example program
#include <iostream>
#include <string>
#include <stdio.h>
#include <math.h>

bool ptb2(float a, float b, float c, float *x1, float *x2);
void gpt();

int main() {
 int tieptuc = 1;
 while (tieptuc) {
    gpt();

    std::cout<< "Tiep tuc? (1 - Tiep tuc, 0 - Stop)";
    std::cin >> tieptuc;
 }

 return 0;
}

void gpt()
{
  float x1, x2;
  float a, b, c;
  std::cout<< "Nhap a: "; std::cin>>a;
  std::cout<< "Nhap b: "; std::cin>>b;
  std::cout<< "Nhap c: "; std::cin>>c;
  if (ptb2(a, b, c, &x1, &x2)) {
      printf("x1 = %f, x2 = %f\n", x1, x2);
  } else {
     printf("Vo nghiem\n");
  }
}

// Ham ptb2 giai phuong trinh bac 2 co 3 he so a, b, c. Ham tra lai true neu co nghiem, false neu vo nghiem
// Trong truong hop co nghiem thi nghiem duoc luu vao x1, x2
bool ptb2(float a, float b, float c, float *x1, float *x2) {
    float delta = b * b - 4 * a * c;
    if (delta < 0)
        return false;
    *x1 = (-b + sqrt(delta))/(2*a);
    *x2 = (-b - sqrt(delta))/(2*a);
    return true;
}