# Favorite Equation?

## What's your favorite chem/physics/math equation?   1 member has voted

1. ### 1. What's your favorite chem/physics/math equation?

• PV=nRT
14
• e=mc^2
25
• F=ma
15
• e^(pi*i) + 1 = 0
22
• Fg = -G(m1m2/r^2)er
7
• integ(uv) = uv - integ(v du)
5
• a^2+b^2=c^2
10
• zeros(ax^2+bx+c) = (-b +- sqrt(b^2-4ac))/(2a)
3
• e=nhv
0
• Other
31

## Recommended Posts

*sigh* There's always someone waiting to bring down the tone of the place...

;-)

• Replies 85
• Created

#### Popular Days

$4\pi r^2 = 2(\pi r(2r))$

Surface of a Sphere = Surface of Cylinder of equal radius and height.

AND, any slice of a sphere between two parallel planes has the same area as a cylinder the same height with a radius equal to the original sphere.

##### Share on other sites

Girls=Evil etc etc

I like that equation the best

##### Share on other sites

6: ultraviolet voodoo!

Not that hard to explain.

We know that:

[uv]' = u'v+uv'

If we take the integral on both sides, we get:

int([uv]')dx = int(u'v)dx + int(uv')dx

(assumes that x is the variable in the equation)

int([uv]')dx = uv, so:

uv = int(u'v)dx + int(uv')dx

The sollutions are then:

(1): int(u'v)dx = uv - int(uv')dx, and

(2): int(uv')dx = uv - int(u'v)dx

Not more woodoo than that.

##### Share on other sites

god, as always, e=mc2 gets the votes simply because people recognize it better

I do agree with that to some extent. One of the reasons that people recognize it better is because it is a very important equation.

##### Share on other sites

$e^{i\pi} = -1$

...and

$1 = \int_{\alpha}^{\rho} e^{-rx}m(x)l(x)dx$

It's an equation so simple but so usefull in evolutionary ecology.

##### Share on other sites

• 6 months later...
What's your favorite equation from chemistry/physics/mathematics?

If yours isn't listed' date=' choose other and reply with it![/quote']

This equation has the answer to GRAVITY and Cold Fusion

theorein

##### Share on other sites

I'm a fan of Henderson-Hesselbach.

##### Share on other sites

${\cal L} = \bar \psi \left( i \gamma^{\mu} \partial_{\mu} -m \right) \psi - \frac{1}{4} F^{\mu \nu}F_{\mu \nu}$

##### Share on other sites

$f_j = \sum_{k=0}^{n-1} x_k e^{-{2\pi i \over n} jk }$

##### Share on other sites

$\frac{(U+C+I)(10-S)}{20}\times A\times \frac{1}{1-\sin{\frac{F}{10}}}$

Any guesses as to what it is?

##### Share on other sites

I like this one too... beauty in simplicity

$\phi = {\sqrt{5}+1 \over 2}$

##### Share on other sites

This equation has the answer to GRAVITY and Cold Fusion
Sound's fun, do we get to see it?
##### Share on other sites

This equation has the answer to GRAVITY and Cold Fusion

theorein

i don't see it

##### Share on other sites

$ln(2)=\sum^{\infty}_{k=1}{\frac{(-1)^{k+1}}{k}}$

mercator series when x=1.....lovely expression for ln(2)

##### Share on other sites

$e^{i\pi} + 1 = 0$ wins out for me every time! Simply because it lists so many importannt and intresting things in it

$E=mc^2$ Comes in a close second and any of the others could be third depending on my mood

Cheers,

Ryan Jones

##### Share on other sites

Typo: Integration by parts is:

integral(u dv) = uv - integral(v du)

Personally, I like translation of coordinates with Jacobian...

doubleintegral(F(x,y)dy dx) = doubleintegral(F(x(a,b),y(a,b))J((x,y),(a,b))db da)

=Uncool=

##### Share on other sites

Mine is $a + b = b + a$

Too often we take commutativity for granted!

##### Share on other sites

Uncool, use LaTeX, it's so much more attractive.

$\int u\cdot dv = uv - \int v \cdot du$

$\iint f(x,y)\cdot dy\cdot dx = \iint f\Big(x(a,b),y(a,b)\Big)j\Big((x,y),(a,b)\Big)\cdot db \cdot da$

##### Share on other sites

Well so far for me it's $E=mc^2$ simple, elegant and holds far reaching implications.

##### Share on other sites

Mine is a=lw because it helped me get through many years of elementary school.

##### Share on other sites

v=fw

(lol here w= wavelength, dont know how to use latex and cant find the symbol thingie for wavelength.)

why? because this is the very first formula i learnt in my physics class! (about 3 weeks ago)

##### Share on other sites

dont know how to use latex and cant find the symbol thingie for wavelength
You mean lambda? That'd be λ. In LaTeX it'd be: $v=f\lambda$. (Click on any LaTeX image for teh code).

Thanks heaps XD

##### Share on other sites

I describe necessary vacuum currents to solve for what's implied when you say 'Gaussian wave packet'. This should be the RHS of the Maxwell current eq: j = (-lambda^2 + rho/U) A . THUS IS THE VACUUM NOT A VACUUM

## Create an account

Register a new account