REACH THE IMPOSSIBLE DREAM In the situation in which somehow, in some fashion, by some trick - this 2 different series (see below) had a \[\color{red}{\bf FINITE\quad Total \quad Sum}\], what would such Total Sums be ? First series \[\sum_{k=1}^\infty \frac{1}{k}\] Second series \[\sum_{k=1}^\infty (-1)^{k+1}\] What would the sums be ?
Solutions Exists.
But this is infinite @sauravshakya
id like to know what is solution...so watching :)
ME too.
Well there was a MAN from your part of the world... VERY famous.... mystical mathematician... numbers were his personal friends 1) Who was HE ? 2) How does he help you in that ?
CALCULATOR
@estudier
Are u sure the question is correct....... i think it is 1/k instead of 1/n
Cesaro/Grandi
Abel
You get nothing @estudier . You are the destructor of PLEASURES
THE SECOND ONE IS 0
1/2
I think for first one it is greater than 2
Divergent series upset the calculs addicts....
\[ Lao\,\, Tzu\,\,\,says\,\,\, \text{There is no such thing as divergent series} \]
No, that was Sum Tzu..
Rubbish estudier, tat guy was only a stupid general
Um, you didn't get my little joke....(sum not sun)
Yes I got it - but the mind was faster then the hand.
WELL, if @Mikael THE ONE WHO KNOWS EVERYTHING HAS ALREADY SOLVED THEN WHY SHOULD I DO IT......
Look Abel summation or Cesaro summation - AND PLEASE SOLVE IT here. PLease!
Grandi series
The real understanding comes from Abel summation !
Cesaro
I thought everyone knew that one.....
im back... lol
@mukushla is brilliant in solving problem.......... @Mikael
One of best talent I have seen.
But you didn't look up Cesaro or Abel summation
1+1+2+5+14+42+...= 1/2 - i sqrt3/2
@sauravshakya @mukushla this sneaky French guy (cannot say his name) is stealing your chance at glory
which glory ?
1 +2 + 4 + 8 +16 +....=-1
Somming DIVERGENT SERIES
thats not real :)
Them Catalan numbers again..........:-)
Neither are imaginary numbers......
Yep the Catalan numbers are back @estudier
http://en.wikipedia.org/wiki/Ces%C3%A0ro_summation http://www.encyclopediaofmath.org/index.php/Abel_summation_method
@sauravshakya please read and apply to these two series
or Mrs. @satellite73 or @experimentX ?
lol ... you should be putting Mrs.
second one is in the link you sent
I meant- gentlemen ?
a quick google search turns up euler mascheroni constant for harmonic series, which also seem so be \[\lim_{n\to \infty}\sum_{k=1}^nk-\ln(n)\]
\[ \sum_{k=1}^\infty (-1)^{k+1} = 1 - 1 +1 - 1 + 1 ... \\ \] some guy had me shown some trick that it converges to 1/2 ... don't remember it though.
that is NOT A SOLUTION!
http://en.wikipedia.org/wiki/Ces%C3%A0ro_summation http://www.encyclopediaofmath.org/index.php/Abel_summation_method
As you know \[ \ln(n) \to \infty\]
So Mascheroni is NOT the answer
\[ \text {Let } 1 - 1 +1 - 1 + 1 -1 + ... = a \\ 1 - (1 - 1 + 1 - 1 ...) = 1 - a = a \implies 2a = 1 \implies a = {1 \over 2 }\]
this is false ... . of course :D
By simple trick \[ \sum_{k=1}^\infty \frac{1}{k} \] it can be shown to be divergent ... for I don't remember any sleight of hand on this. Let's think for a while.
http://en.wikipedia.org/wiki/Ces%C3%A0ro_summation http://www.encyclopediaofmath.org/index.php/Abel_summation_method
FOR Ramanujan's sake READ !
Messrs. @experimentX @satellite73 @sauravshakya
1-1+2-6+24-120+......
That will only work with Abel x> 5
Too divergent - works with Double-Abel
1-2+3-4+....
Cesaro is enough for that
The nasty one is 0.6 or thereabouts.....
The nasty one is 0.6 or thereabouts.....
Hey people - how can one cause you to read ?
Ah ... i was working on project euler problems.
Man I flunked in life for the first time on on analysis.
You need divergent sum therapy....:-)
How do you plan to sum with Abel summation?
\[\lim_{x\rightarrow 1-0} \sum_{k=0}^\infty a_k x^k = S.\]
\[\Huge \lim_{x\rightarrow 1-0} \sum_{k=0}^\infty a_k x^k = S.\]
go on ...
."..it is no more doubtful that the sum of this series 1−2+3−4+5 + etc. is 1⁄4; since it arises from the expansion of the formula 1⁄(1+1)2, whose value is incontestably 1⁄4." Euler
interesting ... how do you do that?
1⁄(1+1)2 = 1/2 ( 1 - 1 + 1 - 1 + 1 - 1 ... )
half of half is a quarter......!
how did you manage to get n's in coefficient.
let's tyr this \[ {1 \over (1 + x)^2} = \] http://www.wolframalpha.com/input/?i=expand+1%2F%281%2Bx%29^2 Idiot me!!
http://en.wikipedia.org/wiki/1_%E2%88%92_2_%2B_3_%E2%88%92_4_%2B_%C2%B7_%C2%B7_%C2%B7
should have noted.
Scroll down to Euler and Borel
Sorry, to Abel Summation....
Interesting!!
encountering this material for the first time man!!
Good So just dive in and understand it "like a boss"...
Hhaha i wish i could understand it "like a boss" ... I a bit slow. especially on algebra and analysis.
Plug the sequence into the expression and try to find the limit
The harmonic series is easily summed by Cesaro Summation
Cesaro. Never heard of it. Thanks for bringing it accross.
\[ \int {1 \over 1 -x}dx = \sum_{n=1}^\infty {x^n \over n }\] I wonder if this is useful.
the partial sums are \[ {1}, {3 \over 4}, {11 \over 18}, {25 \over 48}, ...\]
this seems to sonverge to zero as n->inf
this is bugging me \[ \lim_{m\rightarrow \infty} {1 \over m }\sum_{n=1}^m {1 \over n } \sum_{k=1}^n {1 \over k}\]
I wonder if i can use this http://en.wikipedia.org/wiki/Faulhaber%27s_formula
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