Find the value of:
k = 1 ∑ ∞ k ( 1 + 1 2 k ) 1
The answer is of the form:
A − B ( l n 2 + C l n 3 ) − π ( D + F E ) + G H l n ( I − J )
Find the value of: A + B + C + D + E + F + G + H + I + J
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How did you jump from line 3 to line 4?
Or how do you calculate H(1/12)?
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Actually I used the value of H 1 2 given in Wikipedia. There was a lengthy method to calculate it's value.
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That's the point. It's not easy to evaluate stuff like these. It's better to post this as a note and ask the readers to prove it.
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@Pi Han Goh – I'm trying to evaluate it's value. Once I get with it I'll surely post it.
@Pi Han Goh – I'll post the value of H1/12 tonight.
@Aditya Kumar Have you seen the generalization I have provided to do such sums? If not, you should give it a look at. How Wikipedia calculated H 1 / 1 2 can be explained by using the definition of digamma function and using the same(polygamma function), you can prove a general identity which I have provided in one of the Pi Han Goh's problem. There, I've not provided with the proof though but the generalization is really helpful to remember.
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Finally found the link .
Yes I actually had forgotten to prove that. I'll prove that sometime later as my exams r on. Till then try my new problem. I'm sure you'll solve it.
@Abhishek Bakshi see this and comment.
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You are actually giving free points to people... and why are you wasting your time on the digamma and polygamma functions functions.. it would be better if you prepared more seriously about IIT or for some reputed mathematics institution.. you can do all this after you get into them..
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I am preparing for IIT. It is just that I give 1hr daily to my interests.
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@Aditya Kumar – great, continue... giving free points :-D
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@Abhishek Bakshi – Y not solve all? I see u have solved only 2 of my probs
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@Aditya Kumar – don't have so much free time as u..
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@Abhishek Bakshi – Good joke! Just accept u couldn't solve all. U solved only those which use digamma. Try other probs.
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@Aditya Kumar – oh...really!!!! even if its true, it doesn't matter cause you are a flopshow in the academy tests.... and neither do i have the need to solve all of your unimportant problems..
r = 1 ∑ n r + a 1 = ψ ( n + a + 1 ) − ψ ( a + 1 )
Split the given fraction as k ( 1 + 1 2 k ) 1 = k 1 − k + 1 2 1 1
Taking summations upto n both the sides you get
k = 1 ∑ n k 1 − k + 1 2 1 1 = ψ ( n + 1 ) − ψ ( 1 ) − ψ ( n + 1 2 1 3 ) + ψ ( 1 2 1 3 )
using ψ ( 1 ) = − γ
and
Take limits n to ∞ both the sides we get...
ψ ( 1 2 1 3 ) + γ
I didn't get anything :P. Yor questions appear to me like this
wolframalpha gives directly the partial sum formula for this...
but i didnt know the property u used
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He used polygamma function
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here its digamma
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@Aman Rajput – Yes. I'll start learning it after a few days.
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k = 1 ∑ ∞ k ( 1 + 1 2 k ) 1 = 1 2 1 k = 1 ∑ ∞ k ( 1 + 1 2 k ) 1 2 = 1 2 1 k = 1 ∑ ∞ k ( 1 2 1 + k ) 1 = H 1 2 1 = 1 2 − 3 ( l n 2 + 2 l n 3 ) − π ( 1 + 2 3 ) + 2 3 l n ( 2 − 3 )