Calculating exponential function

[goillini12]

Use the followingformula to calculate the very important constant e:
e = 1 + 1/1! + 1/2! + 1/3! + 1/4! + 1/5! + 1/6!.........
here n! means n factorial, for example 5! = 5x4x3x2x1x = 120.

I need help writing a program to do this

[Ganon11]

OK, what have you done so far?

[goillini12]

i can code a basic factorial such as the factorials from 1 to 5:

#include <iostream> 
using std::cout; 
using std::endl; 
 
int main() 
{ 
   int factorial; 
   cout << "X\tFactorial of X\n"; 
   for ( int i = 1; i <= 5; ++i ) { 
      factorial = 1; 
      for ( int j = 1; j <= i; ++j ) 
         factorial *= j; 
      cout << i << '\t' << factorial << '\n'; 
   } 
   cout << endl; 
   return 0; 
}

But i do not know how to to 1/n!

[weaknessforcats]

But i do not know how to to 1/n!

How does 1/n get involved in a factorial calculation?

[Laharl]

He's using the Taylor Series for e^x with x=1.

Here's a hint: 1/x is the same as x^(-1).

[weaknessforcats]

He's using the Taylor Series for e^x with x=1.

My mistake. I thought he was calculating factorials.