Use the following approximate formula to find an approximation of the reciprocal of Napier's constant e.
1/e = 1 - 1/1! + 1/2! - 1/3! + 1/4! - ･･･
Let's observe how the approximation of the reciprocal of Napier's constant e can be obtained , as the number of terms increases.
You can see that the convergence is very fast.