Favorite Equation?

[Norman Albers]

[math][ik,m] = \tfrac{1}{2}(\frac{\partial g_{im}}{\partial x^k}+\frac{\partial g_{km}}{\partial x^i} - \frac{\partial g_{ik}}{\partial x^m})[/math], and [math]\{^m_{ik}\} = g^{mn}[ik,n][/math]. This took quite a while to learn to compose, yes!!! How satisfying to speak the same language. Party at the TOWER.

[xoxpe]

i like F=ma because it's simple... unlike the others..

 

 

btw, i am a newbie here, nice to meet u all in this forum

[woelen]

cos(pi/5) = ¼ + ¼*√5

 

I like this one most, because I derived it myself as highschool boy, long before I ever had heard of group theory, Galois theory etc. At school we only had to learn cos(pi), cos(pi/2), cos(pi/3), cos(pi/4) and cos(pi/6) as special values. It was very striking to me that cos(pi/5) also has a special value.

[YT2095]

I like: HIO4 + flat raised base = Periodic Table

[BigMoosie]

Number of ways to pick k items from n choices. I like it because I solved it myself before I was studying probability, only to learn that Pascal beat me by several hundred years.

 

[math]^nC_k = \frac{n!}{(n-k)!k!}[/math]

[Sequence]

y=mx+b

 

slope intercept form of an equation. Don't know why I like it.

[Gilded]

I like

mostly because I haven't got the slightest what it's all about. It has something to do with Yukawa interaction between a scalar and a Majorana field.

[Sayonara]

It has something to do with Yukawa interaction between a scalar and a Majorana field.

 

Marijuana field more like

[Guest Veritas]

I have to say my personal favourite is Newton's second law of motion: F=ma. Why? It's simple, sleak and the only one I can remember without thinking for a second. But of course, the three main kinematic relations:

v=u+at

s=ut+0.5at²

v²=u²+2as

and obviously their angular brothers which I don't know how to write the symbols for on the computer.

 

Derek.

[Eureko]

I voted for this (integ(uv) = uv - integ(v du))one cause in Spanish (I am Spaniard) we memorice it with a funny phrase:

 

S(uv) = uv-S(v du). S(uv) = Un Viejo-Salido(Viola Dos Universitarias).

And this means: A green old man raped two universitarian girls.

Funny?

[Fred56]

I like Lagrange (and Laplace) transforms, they're pretty cool.

Or this:

 

 

[math]1... (H=\sum_i \Delta_i X_i)[/math]

[math]2... H=\sum_i (\Delta_i X_i + h_i Z_i) +\sum_{ij} J_ij Z_i Z_j[/math]

[math]3... H=\sum_i h_i Z_i +\sum_{ij} J_ij Z_i Z_j[/math]

[math]4... E=\sum_i h_i s_i +\sum_{ij} J_ij s_i s_j[/math]

 

..which defines a quantum 'process', apparently (and the ordering is crucial). But I only have an idea what it all means (X and Z are the Pauli matrices, at least I know what a matrix is)...