C++ "TÌm kiếm nhị phân"

// Vi du ve bai toan tim kiem nhi phan

#include <iostream>
using namespace std;
float x;

float f(float x){
    return x*x*x + x - 1;
}

int main(){
    float l = -5, r = 5, eps = 1e-5;
    while(r - l > eps){
        float mid = (r + l) / 2;
        if (f(mid) > 0) r = mid;
        else l = mid;
    }
    cout << "Nghiem la " << (r + l) / 2 << endl;
    return 0;
}