Valhalla Legends Archive

But it's like that because you're trying to make them equal to zero.

Quote from: Yoni on December 18, 2003, 04:36 PM
I never understood the American FOIL and similar tricks. We have no such thing. It couldn't be much simpler, just multiply everything by everything else and add all the pairs.
(a+b)(c+d) = ac + ad + bc + bd
What's the big deal?

Hehe.  When I expand I usually do the following:

(a+b)(c+d) = ac + bc + ad + bd

FIOL!

Edit: I think the reason we were taught this method is that it allows us to give the method a name when explaining.  The same can be said for the rainbow method.  "Rainbow it out" or "Foil it out".

The American educational system, nevermind simply refering to mathmatics in general, is totally fucked up and it would seem that the only good teachers are those in colleges (and I've met a few that are pretty dumb though) and unless you have tons of money, you really won't get much out of public education opposed to those obviously in other countries unless your willing to learn on your own.

The math teachers I had in HS were fucking idiots and taught us stuff, but didn't do it efficiently because most kids were just as dumb if not dumber when they left the class. When it came to using calculators, they were depended upon in classes and I remember some classes where we spent the entire time learning how to use a TI-83 and how to manipulate the graphing functions. Then most of the time as stated before, we weren't allowed to use the calculators but had to rely on what we had supposively been taught.

I remember taking my "Intermediate Algebra" class last spring with one of my favorite math teachers and I'll never forget losing my patients with him when he was teaching us logorithms and natural logs.  I had asked him HOW logs worked because of course like most programmers, I want to know how people did logs BEFORE calculators and other bits of technology were around. Of course he didn't understand my question I don't think because I believe he thought I wanted a programatic version of the algorithm instead of explaining it in class which was false. I just think he thought the students wouldn't really care about the actual method.

As a last note about using calculators in math class, we used to play nes games on ours and I loved playing mario on mine

I have mario on mine but hardly play it, I usually play pacman. Infact the TI-83 is what got me in to programming way back in 7th grade.

Quote from: DarkVirus on December 21, 2003, 10:13 PM
The American educational system, nevermind simply refering to mathmatics in general, is totally fucked up and it would seem that the only good teachers are those in colleges (and I've met a few that are pretty dumb though) and unless you have tons of money, you really won't get much out of public education opposed to those obviously in other countries unless your willing to learn on your own.

The math teachers I had in HS were fucking idiots and taught us stuff, but didn't do it efficiently because most kids were just as dumb if not dumber when they left the class. When it came to using calculators, they were depended upon in classes and I remember some classes where we spent the entire time learning how to use a TI-83 and how to manipulate the graphing functions. Then most of the time as stated before, we weren't allowed to use the calculators but had to rely on what we had supposively been taught.

I remember taking my "Intermediate Algebra" class last spring with one of my favorite math teachers and I'll never forget losing my patients with him when he was teaching us logorithms and natural logs.  I had asked him HOW logs worked because of course like most programmers, I want to know how people did logs BEFORE calculators and other bits of technology were around. Of course he didn't understand my question I don't think because I believe he thought I wanted a programatic version of the algorithm instead of explaining it in class which was false. I just think he thought the students wouldn't really care about the actual method.

As a last note about using calculators in math class, we used to play nes games on ours and I loved playing mario on mine

None of my math classes save pre-calculus (Which was a complete waste of time) were dependant upon calculators...and this was a public high school.  If anything, the whole math department shunned the use of calculators.

throughout highschool, I did precalculus which was the same as applied math except we weren't allowed to use calculators at all (well, we *could* for homework, but that's different).  We learned to use TI-83's in physics, but even we didn't use them much (once in awhile).  I found that my teachers were reasonably smart, and I did learn a lot in highschool.

Quote from: DarkVirus on December 21, 2003, 10:13 PM
I had asked him HOW logs worked because of course like most programmers, I want to know how people did logs BEFORE calculators and other bits of technology were around.
...
I just think he thought the students wouldn't really care about the actual method.

I think they typically looked them up in a table. You would have a thick book with numbers in which you could look up say 1.23456 and get the base 10 logarithm of it, 0.0915122. There might also have been graphs of logarithms that you could use to intepolate out your answers. A table wouldn't need to cover other numbers than say 1 <= x < 10, since log10(12.3456) = 1 + log10(1.23456).

I don't think there's any practical way of calculating logarithms, sines for angles and similar functions without using either known values, tables or infinitely repeating formulas (where you keep adding terms until you have the number of significant digits that you want).

Quote from: DarkVirus on December 21, 2003, 10:13 PM
I had asked him HOW logs worked because of course like most programmers, I want to know how people did logs BEFORE calculators and other bits of technology were around.

We used tables like Adron said. A lot of old mathematicians spend their lives  writing tables. There are tables for logarithms, trigonometric functions, 1/x and much more. You can even find a table for pi and its decimals

We also used slide rules for calculations.