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math trix-2

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posted on 24 Jan 2008 07:46:00 IST

howzzzzz thiss???????????

Given any 2 digit number that ends in 5, and it can b squared in the head!

45² = 2025
85² = 7225, etc.

There's a quick way to do this: if the first digit is N and the second digit is 5, then the last 2 digits of the answer will be 25, and the preceding digits will be N*(N+1).

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SUM_{k=1 to infinity} ( 1/k² ) = ( Pi²/6 )

SUM_{k=1 to infinity} ( 1/k⁴ ) = ( Pi⁴/90 )

SUM_{k=1 to infinity} ( 1/k⁶ ) = ( Pi⁶/945 )

SUM_{k=1 to infinity} ( 1/k⁸ ) = ( Pi⁸/9450 )

SUM_{k=1 to infinity} ( 1/k¹⁰ ) = ( Pi¹⁰/93,555 )

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comment by punnima (posted on 24 Jan 2008 07:47:23 IST)

math trix 3 cummin sooon

comment by crack (posted on 24 Jan 2008 11:13:12 IST)

you rock ............................................sis

comment by pottermania1990 (posted on 24 Jan 2008 21:07:24 IST)

pl. prove atleast 1........

comment by nishant13940 (posted on 25 Jan 2008 17:05:57 IST)

good yaar

comment by navin_m29 (posted on 28 Jan 2008 00:23:54 IST)

This method is already known.
But you may not know that this is possible for 3 digit numbers also which has 5 at end.
By the way keep going..........

comment by mukulss (posted on 28 Jan 2008 14:19:37 IST)

SUMk=1 to infinity ( 1/k2 ) = ( Pi2/6 )

can u please prove it................

comment by punnima (posted on 28 Jan 2008 19:12:35 IST)

If you know about complex numbers, you will be able to appreciate one of the great unsolved problems of our time. The Riemann zeta function is defined by

Zeta(z) = SUMk=1 to infinity (1/kz) .
This is the harmonic series for z=1 and Sums of Reciprocal Powers if you set z equal to other positive integers. The function can be extended to the entire complex plane

comment by punnima (posted on 28 Jan 2008 19:13:32 IST)

Here is an amazing formula due to Euler:
SUMn=1 to infinity n-s = PRODp prime (1 - p-s)-1 .

comment by pottermania1990 (posted on 30 Jan 2008 21:27:03 IST)

dosent make sense

comment by sagar90 (posted on 31 Jan 2008 00:37:00 IST)

ye to mujhe bhi pata tha yaar
mujhe to koi bhi natural number ka square nikalneki technique pata hai me jaldi hi use post karoonga
par good work

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