Define two arrays x and f each of size 10 to pass the array
     Define two arrays x and f, each of size 10, to pass the array to a function, named sum.  In main: define array, pass arrays, print out the array and the results on screen.  In function sum, take arrays from main and sum the arrays using the formula below:  sum = 0.5 sigma^size-1_i=1 (f_i + f_i+1)(x_i+1 - x_i) 
  
  Solution
#include <iostream>
 using namespace std;
double sum(int x[], int f[]){
 double result = 0;
 for(int i = 0; i < 9; i++){
 result += (f[i] + f[i + 1]) * (x[i + 1] - x[i]);
 }
 result *= 0.5;
 return result;
 }
int main(){
 int x[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
 int f[] = {10, 9, 8, 7, 6, 5, 4, 3, 2, 1};
 double result = sum(x, f);
 cout << \"Array x: \";
 for(int i = 0; i < 10; i++) cout << x[i] << \" \";
cout << \"\ Array f: \";
 for(int i = 0; i < 10; i++) cout << f[i] << \" \";
cout << \"\ Sum = \" << result << \"\ \";
 }

