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This topic has moved here: Subject: Let's learn how to find the area of a rectangle!
  • Subject: Let's learn how to find the area of a rectangle!
Subject: Let's learn how to find the area of a rectangle!


Posted by: Snipers Paradox
Posted by: XxBLU JELLOxX

Posted by: Snipers Paradox
Why go through so much trouble just to find the area of a freaking rectangle?


This so fits the thread

My sound card is broken.


Oh well I guess you can't hear it....

  • 02.05.2011 10:38 AM PDT

-blam!- Was that actually blammed out? Or did I just type it? You'll never know.

I wish I had known this to mess with my grade six math teacher.

  • 02.05.2011 10:39 AM PDT

*Facepalm*
and what gun doesn't tear though flesh? a squirt gun?

Forklifts don’t die. They’re just missing in action.

Pooping isn't something I enjoy, nor is it something that takes time. I get in there, drop the packages, then get out. I'm like UPS. What can brown do for you?

Posted by: Disambiguation
Posted by: Dark Martyr 117

Posted by: Hank
You're not as cool as Mister Math.

Agreed. I love how some of the "higher up" members have been quite intimidated by his intelligence lately though...
Mister Math, myself and a handful of others are all members of an elite secret society of mathematicians, engineers and scientists.
This secret society of you are in has 5 days to make a working Minovsky Ultracompact Fusion Reactor.

  • 02.05.2011 10:53 AM PDT

"The individual has always had to struggle to keep from being overwhelmed by the tribe. If you try it, you will be lonely often, and sometimes frightened. But no price is too high to pay for the privilege of owning yourself."
-Nietzsche

Posted by: Randomhero123
Consider a rectangle of height h and width w lying in the XY plane, with one corner at (0,0) and extending in the positive XY quadrant. If we take an element, it will have height h and length dw, giving an area of h*dw. Integrating from 0 w gives us h*w as the area.

My favorite way :)

It's better if you use an area element dhdw. Of course, the answer is always the same.

  • 02.05.2011 10:56 AM PDT

This thread makes me feel dumb.

I hate you all.

  • 02.05.2011 10:56 AM PDT
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MROS (Mindless Rabble of Scientists) - A group to discuss any aspect of science

Posted by: R3ACTlON
Hard is good.

lol

  • 02.05.2011 10:57 AM PDT

RIP Ginger

Spring 1997 - 6 January 2012

Base*Perpendicular Height.

  • 02.05.2011 10:58 AM PDT
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God?

Religion does not provide a sense of morality, but an obedience to authority.

Join Secular Sevens - A group for atheists, free thinkers, skeptics or theists looking for a good debate.

Some one prove that V=(4/3)pi*r^3 for a sphere using Calculus!

[Edited on 02.05.2011 10:59 AM PST]

  • 02.05.2011 10:59 AM PDT

length*width=area

  • 02.05.2011 10:59 AM PDT

',:|

That's awesome.

  • 02.05.2011 11:00 AM PDT

"The individual has always had to struggle to keep from being overwhelmed by the tribe. If you try it, you will be lonely often, and sometimes frightened. But no price is too high to pay for the privilege of owning yourself."
-Nietzsche

Posted by: Gman5434
Some one prove that V=(4/3)pi*r^3 for a sphere using Calculus!
Consider a sphere of radius R centered at the origin, described by the equation x^2 + y^2 + z^2 = R^2. We wish to find its volume.

An appropriate coordinate transformation would be:

x = r*sin(p)cos(t)
y = r*sin(p)(sin(t)
z = r*sin(p)

With domain D = {0 <= r <= R, 0 <= t <= 2pi, 0 <= p <= pi}

The determinant of the Jacobian matrix for this transformation is r^2*sin(p)

The volume of the sphere is then given by the triple integral over D of

r^2*sin(p)drdpdt.

Since the terms are independent, the volume integral can be expressed as the product of simple integrals, resulting in the following:

Integral of r^2 from r = 0 to R
Integral of sin(p) from p = 0 to pi
Integral of dt from t = 0 to 2pi

Which evaluates to

(1/3)r^3|0,R --> (R^3)/3 - 0 = (1/3)R^3
-cos(p)|0,pi --> -(-1) - (-1) = 2
t|0,2pi --> 2pi

Multiplying the results yields V = (4/3)*pi*R^3

  • 02.05.2011 11:22 AM PDT