```
#include <iostream>
#include <cmath> // appropriate c++ libraries for functions & constants needed
#include <fstream>
#include <stdlib.h>
using namespace std;
const int N = 1000;
const double pi = 3.14159265; //constants applied
int main()
{
double num, factor, avg = 1.0; //variables declared and initialised
int i;
num = N - 1;
factor = (N - 1) / N;
for(i=2;i<=N;i++) //loop initiated and calculation
{
avg = avg + factor;
factor = factor * (N - i) / N;
}
cout << "Approximately, the average number of random songs played before a repeat song is "
<< (sqrt(pi * N / 2.0) - 1.0 / 3.0 + sqrt(pi / (2.0 * N)) / 12.0 - 4.0 / (135.0 * N)) << endl; //output message on the command prompt and tabulated answer to the formula/equation
{
ofstream out("Z:\mp3.txt");
if(!out) { //output in command DOS being transferred to
cout << "Cannot open file.\n"; // to the 'Notepad' programme
return 1;
}
out << "Answer is:" << (sqrt(pi * N / 2.0) - 1.0 / 3.0 + sqrt(pi / (2.0 * N)) / 12.0 - 4.0 / (135.0 * N)) << endl;
out.close();
system("Notepad.exe Z:\mp3.txt") ; // ‘Notepad’ programme opens with answer saved to a created ‘mp3’.txt
return 0;
}
}
```

List the functions used and their parameter lists

List key variables used in each function and their interpretation

doin a few exercises out of a text book of mine, and these two Q's are included, just want a bit of help on them.

would i be right in saying functuions here is only the int main () or is the loop a function as well?