Question

I solved it myself and my result is (n+1)/n. Why is that 1/2 there? An explanation would be great if possible. Thanks!

Answer 1

The product of (k + 1) series starts with 3 (because k = 2) and you need 2 to be multiplied to this in order to get (n + 1)!

Therefore you need to multiply 2 and 1/2 to make it right. 2 completes the factorial and 1/2 remains.

Hope it was clear explanation.