Написать программу решения уравнения у(х).

 double x, a, b;
cin >> x;
a = exp(-x);
b = sin(x);
b *= b;
cout << (acos(a) + sqrt(2 - b)) / sqrt(a * (1 + b)); 

 #include <iostream>
#include <cmath>

constexpr double eiler_num = 2.7182818284;
constexpr double pi = 3.1415926535;

double GetRadian(const double angle){
   return angle * (pi/180);
}

double upper(const double x){
   double ei_deegre_neg_x = pow(eiler_num, -x);
   double arcos_ei = acos(ei_deegre_neg_x);
   double one_add_cos = 1 + pow(cos(x), 2);
   double sqrt_cos = sqrt(one_add_cos);
   double returned = arcos_ei+sqrt_cos;
   return returned;
}

double lower(const double x){
   double ei_deegre_neg_x = pow(eiler_num, -x);
   double one_add_cos = 1 + pow(sin(x), 2);
   double temp = ei_deegre_neg_x*one_add_cos;
   double returned = sqrt(temp);
   return returned;
}

int main(){
   double x;
   std::cin>>x;
   double y = upper(x)/lower(x);
   std::cout<<y<<std::endl;
   return 0;
}