#Summarize the sum???
61 messages · Page 1 of 1 (latest)
mhm idk really
how did u find it?
u express 3 as n+2, like a general term
u feel me?
we basically use summation, taking the numerator as n+2 denominator as (n+2)! + (n+1)! + n!
taking n from 1 to 2018
yea
I understand
try and tell me if u still didnt get it
like this
I'm wrong ik ........
yess
but how to continue summarization?
mhm yep
yes now think for a while how can u convert it
oke
got it?
I don't think so......
can u tell what is the basic requirement for telescopic
serial limits??
umm, i mean like a (-) in the numerator lmao
mmm?
okay ill give the solution
yea
sorry i dont know how to express in this way
and then u get 1/(n+1)! - 1/(n+2)!
I get $\frac{1}{2}-\frac{1}{2020!}$
Jay
I got the same answer
Also ended up with this cool infinite series from adapting the problem.
I got the same result, but as
\begin{align*} &\frac{2}{0!+1!+2!}+\frac{3}{1!+2!+3!}+\frac{4}{2!+3!+4!}+... \ &=\sum_{k=1}^{\infty}\frac{k+1}{(k-1)!+k!+(k+1)!} \ &=\lim_{n\to\infty}{\sum_{k=1}^n\frac{k+1}{(k-1)!+k!+(k+1)!}} \ &=\lim_{n\to\infty}{\sum_{k=1}^n\frac{k}{(k+1)!}} \ &=\lim_{n\to\infty}{\sum_{k=1}^n\left(\frac{1}{k!}-\frac{1}{(k+1)!}\right)} \ &=\lim_{n\to\infty}\left(1-\frac{1}{(n+1)!}\right) \&=1 \end{align*}
Jay
cool
ty