Saturday, April 16, 2011

Cauchy Product (1 − 1 + 1 − 1 + ... )

Perquisites :


 given


Cauchy product
\begin{array}{rcl}
c_n & = &\displaystyle \sum_{k=0}^n a_k b_{n-k}=\sum_{k=0}^n (-1)^k (-1)^{n-k} \\[1em]
 & = &\displaystyle \sum_{k=0}^n (-1)^n = (-1)^n(n+1).
\end{array}
then, the product is 
\sum_{n=0}^\infty(-1)^n(n+1) = 1-2+3-4+\cdots.
therefore,
(1)
based  on geometric series (GS.ID.1)
 \sum_{k=0}^{n} a r^k = \frac{a}{1-r}. 
(2)
a=1 , r=-1 in the following equation
(3)
from (2) and (3)
(4)


from (1) and (4)

Monday, April 11, 2011

Riemann zeta function


firstly , I recommend you  to read these  Riemann zeta function  , Euler product  to have fundamental understanding of the Riemann zeta function.

 RZ.ID.1:  

 
p is a prime number

 
Proof
  given

(1)


(2)

(3)
cancelling out the similarities, therefore 
(4)

 RZ.ID.2: 


Proof
derived by multiplying (1) and (4)


 RZ.ID.3:  


proof:



 by differentiating the above equation
 



 RZ.ID.4: 


Proof

(1)
replacing

therefore,
(2)


from (1) and (2)
 


multiplying and dividing  by -1


Sunday, April 10, 2011

Bernoulli-Zeta functions

BZ.ID.1: Bernoulli-Zeta relation
 

Proof

 
(1)
based on the following identity

(2)
substituting (2) into (1)


(3)

(4)

derivative of constant , which is 1, equals = 0
(5)
 

(6)
 
(7)

(8)

if=k=2k

if n=k+1





Wednesday, April 6, 2011

Cauchy Product (Series convolution )

This post will help students understand the derivation of harmonic series through Cauchy Product 

Given identities:

Logarithmic Function

 
(1)
Geometric Series


(2)
Harmonic Series
(3)
product of (1) and (2)

 based on (SC.ID.1)
  

therefore,

therefore, 


(4)
if x=1/2
 

Integration of (4)