Find the sum of these following series.

Question

1. 1 + 1/1! + 1/2! + 1/3! + ..................
2. x - x×x/2! + x×x×x/3! - x×x×x×x/4! + x×x×x×x×x/5! - ...................
3. x + x×x/2 + x×x×x/3 + x×x×x×x/4 + x×x×x×x×x/5 + ...............

Pls Answer immediately ....

Answer 1

After thinking a lot:
1234598765😂😂😂😂

Answer 2

1. e
2. 1-e^(-x) maybe
3.log(1+x)

Answer 3

It's hard to write the whole program. So, here's how you can do it.
1) Define a function for factorial.
2) Scan x.
3) Use a loop from n=1 to (a large number)
(ii) sum += pow(-1, n+1) * pow(x, n) / fact(n);
(iii) sum += pow(x, n) / fact(n);

Answer 4

The first one is a common equivalence to e (2.71828...)
The second one is the Taylor expansion for e^x.
The third one is the Taylor expansion for
-ln(1-x).