How do you evaluate such a large expression even using calculators? (10^9 - 1)!! Note: !! stands for "double factorial function". Please help and many thanks.
(10^9 - 1)!! =
1 * 3 * 5 * 7 * ......* (10^9 - 3) * (10^9 -1) =
The product of all the odd positive interegers from 1 to 10^9 -1
This product is extremely large.....WolframAlpha shows
≈ 1.58084425021110638757272554931990100564787932540... × 10^4282852759
