Вычислить значения выражений

#include <iostream>
#include <string>
#include <math.h>
 
using namespace std;
 
double a(double x){
    double chislitel = 0;
    double znamenatel = 0;
    chislitel = pow(x, ((double) 1 / 3));
    chislitel = pow(chislitel + x, ((double)1 / 3));
    chislitel = pow(chislitel + x, ((double)1 / 3));
 
    znamenatel = pow(x, ((double)1 / 2));
    znamenatel = pow(znamenatel + x, ((double)1 / 2));
    znamenatel = pow(znamenatel + x, ((double)1 / 2));
 
    return chislitel/znamenatel;
}
 
double b(double x,double a) {
    double chislitel = 0;
    double znamenatel = 0;
    double pi=atan(1) * 4;
    chislitel = pow(pi, ((double)1 / 3));
    chislitel = pow(chislitel + a, ((double)1 / 3));
    chislitel = pow(chislitel + x, ((double)1 / 3));
 
    znamenatel = pow(log(a)+log(pi), ((double)1 / 2));
    return chislitel / znamenatel;
}
 
double c(double x, double a,double b) {
    double chislitel = 0;
    double znamenatel = 0;
    
    chislitel = pow(10, ((double)1 / 2));
    chislitel = pow(chislitel + 3, ((double)1 / 2));
    chislitel = pow(chislitel + 2, ((double)1 / 2));
 
    znamenatel = tan(x/(a*b));
    return chislitel / znamenatel;
}
 
int main(){
    int x = 0;
    cout << "Vvedite x: ";
    cin >> x;
 
    double A = a(x);
    double B = b(x, A);
    double C = c(x,A,B);
 
    cout << "a= " << A << endl;
    cout << "b= " << B << endl;
    cout << "c= " << C << endl;
    
    system("pause");
    return 0;
}