I have to write code for class that sums numbers up to a certain point like 5 billion using an increment that we put in using cin, so if we start at 0 and go to 5 billion by increments of 2 it would be like 0+2=2 2+2=4 and so on. When i cout my sums they always read zero can anyone help

Code:#include <iostream> #include <iomanip> using namespace std; int main () { /* Declared Integers*/ double dsum, dx, da, i, ep, ci, pl; /*Assign Variables*/ cout << "What is your starting point using a decimal"<< endl; cin >> dx; cout << "What is your ending point using a decimal"<< endl; cin >> ep; cout << "What is your counting increment using a decimal"<< endl; cin >> ci; cout << "How many times should a sum be printed" << endl; cin >> pl; dsum = 0.0; da = 1.0; /* Prints Columns */ cout << "Line" << "\t" << "Every "<< pl<< "th" << "\t" << "Sum" << "\n" << endl; /*Sums the Numbers*/ while (da<=pl) { i = 1.0; while (i <= ep/pl) { dsum = dsum + dx; i++; dx+ci; } /* prints out the numbers*/ cout << setprecision(20)<< da << "\t" << (ep/pl)*da << "\t" << dsum << "\n" << endl; da++; } system ("pause"); return 0; }