BF2S Forums Calculus Help

x=0 is one solution, but there's another time when x(2y-x^2) = 0, and that's when (2y-x^2) = 0. So x^2 = 2y, x = root(2y). So you'll have an asymptote along the line y = x^2 / 2 .

I'm pretty sure that's how it goes. I haven't taken calculus in many years, but don't worry, I am a math person. [Matter of fact, next week I take the final for the last math class I ever have to take again! Finally!]

I'm currently in a class called "Mathematics of Engineering". It's like an expansion of Differential Equations and more in-depth. There are 3 parts to this course but I'm only required to take the first one.

I took Calculus in high school (2 parts). Then in college I've taken Multivariable calculus (2 parts), Linear Algebra (1 part), and Differential Equations (1 part).

I suck terribly at DE's and linear algebra, but I did alright in calculus. Luckily in high school I had one of the best teachers ever and everyone who took the AP test got a 5, it was crazy. And since I learned it all pretty well in h.s., the multivariable wasn't too much of a problem in college.

Good luck with the rest of your educational career in math

Linear algebra sounds so simple, yet it's kinda hard. It involves matrices. Multiplying them, inverting them, transposing them.

It's very helpful when you have a system of equations that you need to solve simultaneously without having to go through and eliminate an eq one by one. It's also extremely useful in computer programming, and is probably used in games.

In one of my programming classes, we used a program called MATLab, which uses matrices mainly. The teacher said for his master's thesis (or maybe it was PhD), he wrote an immense code that tracked soil particles as a backhoe scooped up a pile of dirt.
Basic understanding of linear algebra does come into play in later math courses (like differential equations), but people who know it really well and know how to program can make some incredible stuff (heck it's probably used in some of the games we play).

mtb0minime wrote:

Linear algebra... ...it's probably used in some of the games we play.

Matrices certainly are. They're used in 3D graphics at least. For doing transformations (rotation, scaling, translation and perspective).

Speaking of which, mtb0minime - I don't suppose you can recall how to invert a 4x4 matrix, can you?

Last edited by Scorpion0x17 (2007-12-06 19:29:48)

I dont know if its in the same thing but i learned a trick to calculate area when you have an irregular polygon and all the coordonates or vector to gt thems...

7,2
4,2
2,4
3,2

then (2*4)+(2*2)+(4*3)-(7*2)-(4*4)-(2*2)  and you get the area. You do cross multiplication, then to the left addition and difference to the right.

rdx-fx wrote:

Scorpion0x17 wrote:

Nice one rdx-fx - you can't imagine how long I've been looking for that!

(though, I must admit, I've not been looking very hard - it's not something I need right now - will be handy for some stuff I want to get round to doing in my spare time though)

Annoying thing is, I used to have a book with all this stuff in it. Thought I still did have a book with it all in. But I'll be damned if I can find it.

In fact the whole site that pdf came from (particularly the source code) will be damned useful.

Matrices and Transformations Anthony J. Pettofrezzo, ISBN 0486636348, 130 pages on one topic.  Reprint of a 1966 book

Handbook of Mathematics ISBN 354043491, 1150 pages. VERY dense and to-the-point encyclopedia of mathematics, with very readable explanations. 5.5"x1.75"x8" (a little bigger than a paperback novel).  It's one of the 5 books that stay on my desk, rather than on a bookshelf.

Handbook of Mathematical Formulas and Integrals ISBN 012382256, 450 pages.  Lists of formulas and tables, with good explanations of how to use them.  (i.e., before the list of integrals, it works out how they're used).

Thanks. 3 more books to add to my 'if I ever get the money to buy these' booklist.

SenorToenails wrote:

Scorpion0x17 wrote:

I don't suppose you can recall how to invert a 4x4 matrix, can you?

Mathematica.

Which'll help me write code to do it in what way exactly?

(I know I didn't say why I wanted to know, but it annoys me when people say stuff like "use Mathematica" - knowing how to do the math is far more useful than knowing how to operate Mathematica).

rdx-fx wrote:

Scorpion0x17 wrote:

Thanks. 3 more books to add to my 'if I ever get the money to buy these' booklist.

ah! gotcha..  poor college student?

The Mathematica site (www.wolfram.com ?) has alot of good content for free.

Also, MIT OpenCourseware has tons of free PDFs and conent.  Think: College courseware, opensourced.

Poor. But not a college student. Just unemployed.

And yeah, I know the information's all 'out there' for free, but as I said, it's only one of those things that I might someday get around to having a go at, so I just hadn't got round to hunting it out yet.

SenorToenails wrote:

Scorpion0x17 wrote:

Which'll help me write code to do it in what way exactly?

(I know I didn't say why I wanted to know, but it annoys me when people say stuff like "use Mathematica" - knowing how to do the math is far more useful than knowing how to operate Mathematica).

While this is true, I didn't know you needed to write it in code.  Knowing how to do the math is important, but once you know how to do it manually, it is FAR easier to use Mathematica when performing a matrix inversion as part of a larger problem.

If you were in a linear algebra class, and used Mathematica for anything but checking answers, you would be setting yourself up for failure.

Indeed.

And ta for the link to yet another book for 'the list'...

SenorToenails wrote:

Scorpion0x17 wrote:

And yeah, I know the information's all 'out there' for free, but as I said, it's only one of those things that I might someday get around to having a go at, so I just hadn't got round to hunting it out yet.

I find it much easier to use a resource that in print as opposed to electronic.  So I also prefer to buy the resources I use a lot.

Yeah, me too.

I sometimes think "I can't wait for electronic paper", but then other times I think "even that's not going to be as good as a real book".

And I hate to think how many trees I've used up printing stuff out!

rdx-fx wrote:

My personal book collection would cost slightly more than my apartment's purchase price to replace..  and about 30x the resale value of my current main car..

Printed out notes?  tons..

Old notebooks?  tons.. 
( http://www.moleskines.com/klmbl15.html are perfect)

Hell.. random old notebook.. let's see..  grid coordinates for tank gunnery course upgrade on Ft. Hood circa 1994(?)
(Was one of the surveyors for that project)


Personally, my next purchase is going to be a tablet PC (laptop).
Tablet PC + huge PDF collection = Happy RDX

I'm sure my book collection will grow.  I haven't sold a single text book since my freshman year, but I'm not quite wealthy enough to be able to buy a lot of the books that interest me.  I have a whole 2 drawer filing cabinet full of old class notes and associated course work.  As for the notebooks, I use these, because they last and are relatively inexpensive.

A tablet PC would be neat, but I'm too poor to buy a second laptop.