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1/(1x3) + 1/(2x4) +... + 1/n(n+2) = n(3n+5)/4(n+1)(n+2)


n=1) 1/(1.3) = 1/3
1.(3.1+5)/4(1+1)(1+2) = 8/24 = 1/3

n-1=> n)

1/(1x3) + 1/(2x4) +... + 1/(n-1)(n+1) =...

2009

Method...

leap: mod(366,7)= 2
not leap: mod(365,7)= 1

leap year : [ mod(year,4)=0 and mod(year,100)<>0 ] or mod(year,1000)=0

Jan 1 , 2004 : Thursday 366 +2

C: |z| = 1/2 is a circle with center (0,0) and radius 1/2

Maybe if we use...

If F holo, C: |z| = r and |a| < r then

F(a) = 1 / (2*pi*j) * INT[ F(z) / (z - a) dz] (Cauchy formula)
...

OOPS!! I NEED GLASSES!!

I agree with Reinsuranc, if the sign is positive the identity is beautiful.

Hmmm... is not an ecuation.

I think...

Cos^2 theta + Sin^2 theta = 1 (Pitagoras)

1 - Cos^2 theta = Sin^2 theta

P(A) = 0.70
P(B) = 0.55
P(A' & B') = 0.20

P(A & B) =??

--------------------

P(A & B) = 1 - P ((A & B)') = 1 - P(A' U B') (De Morgan)
= 1 - [ P(A') + P(B') - P(A' & B') ]

x = cost per hundred
y = units
M = Rachel's money

M = x /100 * y
or M = (x + 0.04)/100 * (y - 5)

xy = (x +0.04) * (y - 5)

...