#include <iostream>
#include <math.h>

double f(double x){
    double a = sqrt(0.6*x+1.7)/(2.1*x + sqrt(0.7*x*x + 1));
    return a;
}

int main(){
    double integral = 0;
    double a = 1.2, b = 2;
    double n = 1;
    double h = (b-a)/n;
    double x = a+h/2;
    while(x<b){
        integral += f(x);
        x+=h;
    }
    std::cout << integral << std::endl;
}