#include "stdafx.h"
#include <iostream>
#include <math.h>
#include <string>
using namespace std;

int fact(int arg)
{
    if(arg < 0)
        return 0;
    if (arg == 0)
        return 1;
    else
        if (arg>2)
        {
      return arg * fact(arg - 1);
        }
}

double perv(int a, double x)
{
    double zn = 0;
    double sum = 0;
  for (int i = 0; i < 5; i++)
  {
      zn = (pow(-1.0, i)/(fact(i)*fact(i + a)))*pow((x/2), 2*i + a);
         sum += zn;
  }
  return sum;
}

double vtor(int a,double x)
{
    double b = 0;
    double cs = cos((a/(57.3))*(3.14159));
    double sn = sin((a/(57.3))*(3.14159));
    if (a % 2 == 0)
        b = (perv(a,x)*cs - perv(a,x))/sn;
    else
        b = (perv(a,x)*cs + perv(a,x))/sn;
    return b;
}
double itog(int a,double x)
{
    return perv(a,x) + vtor(a,x);
}
int main()
{
    cout << itog(4,3.0) << endl;
    system("pause");
    return 0;
}