Ah, Pythagorean Theorem, is there nothing you can't do?

[pokerfan]

The Pythagorean theorem is a celebrity: if an equation can make it into the Simpsons, I'd say its well-known.

But most of us think the formula only applies to triangles and geometry. Think again. The Pythagorean Theorem can be used with any shape and for any formula that squares a number.

Read on to see how this 2500-year-old idea can help us understand computer science, physics, even the value of Web 2.0 social networks.

http://betterexplained.com/articles/surprising-uses-of-the-pythagorean-theorem/">Surprising Uses of the Pythagorean Theorem

http://betterexplained.com/articles/measure-any-distance-with-the-pythagorean-theorem/">How To Measure Any Distance With The Pythagorean Theorem

[Hawkeye-X]

1. Yeah.. I learned it in Gemotry..

a2+b2=c2.

Hawkeye-X

[tabatha]

2. Cool. Thanks.

[SnoopDog]

3. ooohhh, a use for my 'Minor in Mathematics"

x = square root (a squared + b squared)

[Orsino]

23. Heh. I was a physics major.

A chem-major frat brother once tried to tweak me by asking, "How's that Applied Math major?"

My comeback, of which I'm still proud a quarter-century later, was, "Just fine. How are you liking Applied Physics?" :D

Well, you had to be there. And be a nerd.

[moggie]

24. Speaking of nerds

http://xkcd.com/435/

[angrycarpenter]

4. I was my schools first computer student

A single Apple2c was donated to our school in 1984. The math teacher picked me to be the first to play with it. One of the first complex programs I wrote was one to find C and draw a diagram of it. It got me an A++. I don't know how to write Basic anymore but the mention of the pythagorean sure brings back memories.

Still a nerd at heart.

[Redneck Socialist]

5. 1984!?

We were messing around with computers in '79 or '80. Granted we were saving our work on casset tape, but computers non-the-less. 1984 seems late to the party.

[angrycarpenter]

9. my highschool was a joke

It is a wonder I learned anything. The school board resisted a computer class for years. We did not get a real class for three more years. I was long gone by then.

[kickysnana]

15. We were tied into a mainframe about 1967.

One terminal in one classroom for the whole school. You had to have sharp elbows and a resistance to "Minnesota nice" to get enough time to do anything but print out a paper that said "Hello" in "e"s.

:hippie:

[Greyskye]

17. Agreed. We had Trash 80's in '79 or '80

One TRS-80 Model I, and one TRS-80 model II. 4K of memory, cassette tape drive, and an un-debounced keyboard. Fun times! :rofl:

We also had a connection to a local universities mainframe. A couple guys in the class wrote a spoof logon for the mainframe to harvest account names and passwords. If you build it, they will hack!

[Thor_MN]

25. Cassettes? We dreamed of having cassettes. My first programs were stored on paper tape.

Graduated High School in 1981, having never been able to fit the "computer math" class into my schedule, but knowing more about computers than most of the people in my class. It's paying my bills low these many years later despite having picked up a BA in Chemistry along the way.

Most of the programming I did was via a long distance 10 or 30 character per second modem connection to a main frame computer at the nearest university. The only storage I had access to was to print my programs to paper tape - punched holes representing the binary values of the ASCII for the programs I typed.

[pokerfan]

26. Mine too

circa 1977. Mos-Tech 6502 Kim-1. At college, I graduated to keypunch only because they didn't let the freshmen have access to the real computers, a campus wide Amdahl 470 and my EE department's HP-1000.

[central scrutinizer]

16. We started using punch cards in 1967 in high school

and writing programs which were taken to the largest bank in town to run - the only one that had a computer.

[burrowowl]

6. COOL!

K&R and thanks for links

[Old Codger]

7. yup n/t

[ashling]

8. This was around before Pythagoras

I saw a show on BBC the other day called MATHS where they said that this was known to the Babylonians. They have this clay tablet that apparently is proof that it was known to them (to me it looked like my chickens had just run around on it) Ole Pythy was late on the scene

They said that the Babylonians may not have conceptualized it the same way, anyway, the Greeks gave us Proofs ... which apparently changed everything, but I can't be sure about that as I was not around at the time.

:shrug:

[enlightenment]

10. I cannot comment intelligently on this because I am an historian

. . . but I did want to ask: where did you find that copy of my maths test?

I distinctly recall signing off with the X O after cleverly locating 'x'!


(seriously, that's pretty neat information. Thank you for posting.)

[ColbertWatcher]

11. HEY! I was told ther would be NO math!

Mods, please remove this post, post haste!

(That's post squared)

[tblue37]

18. No--you were told that Rove had THE math. (Turns out he didn't, though.) nt

[krispos42]

31. Consensus is...

we like watching you suffer. :P

[BrklynLiberal]

12. Fascinating..

[struggle4progress]

13. It's like Bhaskara's proof, except Bhaskara (1114-1185) didn't provide explanation beyond "Behold!"

http://www.math.hmc.edu/funfacts/ffiles/10013.2.shtml

<on edit:> Perhaps the natural interpretation is that Bhaskara intended an equi-complementability proof: by adding twice the rectangle x*y to the sum of the square on x and the square on y, one obtains the square on x + y; but one also obtains the square on x + y by adding four copies of the right triangle with legs x and y to the square on the hypothesis of that triangle; but twice the rectangle x*y is the same as four copies of the right triangle with legs x and y; since the two squares on the legs plus the two rectangles x*y is the square on the hypotenuse plus the two rectangles x*y, we get the pythagorean theorem

[Kip Humphrey]

14. from the back row... zzzzzzzzzzzzzzzzzzzzz

[Dr. Strange]

19. Something I just noticed.

There are lots of integer solutions to the equation x² + y² = z². But there are no nontrivial integer solutions to x³ + y³ = z³. In fact, there are no nontrivial integer solutions to xⁿ + yⁿ = zⁿ for any n greater than 2. Interesting...

[DavidDvorkin]

20. In fact, I have an elegant proof of your assertion

but lack space to include it here.

[Dr. Strange]

21. Your proof is wrong.

You erroneously assumed unique factorization of algebraic integers.

[DavidDvorkin]

22. If you reject that proof, I have another one

Not very elegant. It uses a computer.

[NYC_SKP]

27. Love it. My favorite is math phenom is still the golden mean.

I occasionally pull it out like a parlor trick, asking an engineer or scientist to solve for X from the equation 1/X=1+X.

[pokerfan]

28. ?

1/X = 1+X
1 = (1+x)x
1 = x + x^2
0 = x^2 + x - 1

x = 0.6180339887498949, -1.618033988749895

:shrug:

(I are a engineer.)

[Dr. Strange]

29. Yeah, that should probably be

1/x = x - 1.

[BlooInBloo]

30. (facepalm) There really oughta be a law against people who know nothing about math...

Saying stupid shit about math.

[pokerfan]

32. I beg your pardon!

What the fuck is with the personal attacks?