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Favorite Equation

Favorite Equation

Science

a

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Do you guys have a favorite equation?

Mine is e^(i*pi)+1=0.

K

Germany

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At the moment, the Gross-Pitaevskii-equation.

m

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Originally posted by amolv06
Mine is e^(i*pi)+1=0.
That is a nice one, though you could argue it's an identity rather than an equation. If you wanted to be picky. 🙂

AThousandYoung
1st Dan TKD Kukkiwon

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F = M/2 +7

A formula for determining how young you should date. If you're 30, then 1/2 of that is 15, +7 is 22. Avoid the 21 and under crowd.

twhitehead

Cape Town

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Originally posted by AThousandYoung
F = M/2 +7

A formula for determining how young you should date. If you're 30, then 1/2 of that is 15, +7 is 22. Avoid the 21 and under crowd.
Neither my father nor sister followed that equation, and so far have had quite successful marriages.

AThousandYoung
1st Dan TKD Kukkiwon

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Originally posted by twhitehead
Neither my father nor sister followed that equation, and so far have had quite successful marriages.
What were your parents' ages when they started dating?

F

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One of the most interesting equations, and one of the most famous ones too, I believe, is this:
a^n + b^n = c^n, where a,b,c is an integer >0 and n is an integer >2.
Fermat got interested in it, and myriads of mathematicians thereafter.

One of the matematicians working with this equation is Sophie Germain (1776 - 1831) who has one of the most interesting life stories. She was a lady matematician in the area no women worked before. There is even a set of integers that is named after her.

The problem is now solved: There are no a,b,c, and n that can solve the equation. This is not interesting. What's interesting IMHO is that a seemingly simple equation is so difficult to deal with. Not many mathematicians can understand the proof. But in its simpler form it is understandable for amateur mathematicians. Like the case n=4 and some more.

Simon Sing brought the attention to this equation in his book "Femat's Last Theroem".

twhitehead

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Originally posted by AThousandYoung
What were your parents' ages when they started dating?
I don't know exactly but about 41 and 21.

s
Fast and Curious

slatington, pa, usa

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One of my favorites: B4IFQ(RU/18)

zeeblebot

silicon valley

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http://en.wikipedia.org/wiki/Maxwell%27s_equations#General_formulation

t

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Originally posted by mtthw
That is a nice one, though you could argue it's an identity rather than an equation. If you wanted to be picky. 🙂
An identity of what?

R
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Originally posted by talvtal
An identity of what?
A mathematical identity is one that remains constant regardless of the values of the variables in it.

ex.

(sin(A))^2 + (cos(A))^2 = 1

no matter what value you substitue for "A" the equation is true.

although now I'm slightly confused because there are no variables in e^(pi*i) = -1

?

Edit: ok actually its just a special case (x=pi) of

e^(ix) = cos(x) + i*sin(x)

R
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Originally posted by joe shmo
A mathematical identity is one that remains constant regardless of the values of the variables in it.

ex.

(sin(A))^2 + (cos(A))^2 = 1

no matter what value you substitue for "A" the equation is true.

although now I'm slightly confused because there are no variables in e^(pi*i) = -1

?

Edit: ok actually its just a special case (x=pi) of

e^(ix) = cos(x) + i*sin(x)
And while im at it

I don't have a favorite yet, but one i'm currently looking at

y" + (k^2)y = 0

its soluion relates to Eulers identity.

twhitehead

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Originally posted by joe shmo
A mathematical identity is one that remains constant regardless of the values of the variables in it.
Don't all equations have that property?

m

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Originally posted by twhitehead
Don't all equations have that property?
Contrasting with an equation, which is true for particular values. A simple example:

2x = x + x, is an identity
2x = x + 1, is an equation with the solution x = 1.

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