Week #4
Where should you be? At the beginning of course, we're back again looking at secant and tangent lines. This week we will look more closely at the process to figure out the 'derivatives', that is we are going to take the slope of the secant line as a difference quotient and then move the points together to find a new function that we call the derivative, because it is derived from the original function. Essentially the two points on a function f(x) will be:
(x, f(x)) and (x + h, f(x + h)), then the difference quotient or slope of a line containing those points, finally a limit as h -> zero. Sounds easy, but there's much more detail to come.
Oh, also, almost everyone got a perfect score on quiz #2. The actual quiz and solutions are posted. I'll give back your papers on Monday.
But a warning too. IT IS UNACCEPTABLE TO LOOK AT YOUR NEIGHBOR WHILE TAKING THE QUIZ! I saw many people looking at their neighbor's property. That is a BIG NO-NO! For some, that's a warning shot over your bow, next time I see it I will send in a direct hit, and yes, your boat will sink. I don't take prisoners and will not throw out a floatation device.
(x, f(x)) and (x + h, f(x + h)), then the difference quotient or slope of a line containing those points, finally a limit as h -> zero. Sounds easy, but there's much more detail to come.
Oh, also, almost everyone got a perfect score on quiz #2. The actual quiz and solutions are posted. I'll give back your papers on Monday.
But a warning too. IT IS UNACCEPTABLE TO LOOK AT YOUR NEIGHBOR WHILE TAKING THE QUIZ! I saw many people looking at their neighbor's property. That is a BIG NO-NO! For some, that's a warning shot over your bow, next time I see it I will send in a direct hit, and yes, your boat will sink. I don't take prisoners and will not throw out a floatation device.
posted by Ron Bannon at
9/24/2004 11:40:00 AM
8 Comments:
I once mentioned in class -- no, you are not responsible for this -- something about the behavior of mathematicians. Well, they often get excited over what others see as nonsense. For example, the NFSNET project is to using the Number Field Sieve to find the factors of increasingly large numbers. Projects like these require a lot of computational power, and almost anyone can participate by letting their machines work on small pieces of the problem, and I've been doing so for about 10 years now, not just on one project though. Anyway, today I received an email that the completion of the factorization of 11^199 - 1 is done. This, of course, is a big announcement.
Using Mathematica, you'll easily find that: 11^199 - 1 = 11 726 411 604 186 016 583 747 109 512 685 560 309 623 483 854 554 434 407 388 410 414 639 784 223 789 081 037 046 056 424 175 753 141 648 716 527 748 945 549 540 857 806 215 264 173 910 909 628 312 940 005 671 566 125 086 878 597 894 212 880 871 602 378 558 606 937 088 081 090
(The spacing is to make this large number easier to read.)
Now, using Mathematica, enter: FactorInteger[11^199 - 1]
And you'll be there forever. Factoring integers is a tough business.
By
Ron Bannon, at 8:52 AM
Many new links related to distributed computing projects have been posted in the lower right sidebar.
By
Ron Bannon, at 8:02 PM
I have a rather non mathematical question Mr. Banon. i have intended to download the answer keys for the quiz, but i have noticed that the file downloads with an extension .key wich, i understand is a registry key. i was wondering, what is the purpose of it if not desire to tinker with ones registry. i might be wrong about it. so i will do my research. and if my suspition is supported. well ...
until than i will remain mad.
with love, Anonimous
By
Anonymous, at 8:43 PM
No need to be mad, but I understand your confusion. Read on for possible enlightenment . . .
Well, the file is actually just a jpeg file. The full name is MTH.121.Quiz.02.key.jpg, and you should notice that the extension (jpg) is part of the full file name. In any case, when you click on this link your browser should open the file for you, but, under some circumstances you may need to use an external jpeg file viewer. Let me know if you have any problems.
Can you read the quiz file, it's a pdf. The reason I use jpeg for the answer key is that it's a scan, but I can always convert this to pdf if that's preferred. Just let me know.
By
Ron Bannon, at 9:39 PM
Quiz 2 was a breeze compared to Quiz 1 - I studied hard because I expected the same difficulty... I hope it paid off.
Gbenga
By
Anonymous, at 9:16 PM
"I cannot tell. Those that do teach young babes, Do it with gentle means and easy tasks: He might have chid me so; for, in good faith, I am a child to chiding." -- William Shakespeare, Othello
By
Ron Bannon, at 7:14 PM
Enligtened but not satisfied.
i tryed two ways of saving the file:
1. rightclick link to quiz key and choose "save target as..." which nicely and smoothly saves itself as JPEG.
2. right click on open image and choose "save picture as" which is a problem. it downloads on desktop with extension .key and shows registry key icon. thats probably because of .key extension; but as u say it should open itself as an image; but, when i click on it, it pops up with an option if i want to add a key to my registry; and i really dont want to. :). i also opened it with a hex editor. and extension looks like JPEG and nice and harmless. but then what would i know about the rest of the hex abrakadabra. oh, by the way i also thought confusion was caused by my system settings but i tryed opening it on 3 different computers(all 3 pc) and result is the same.
im sure the file is harmless but causing confusion. it would be a good practice not to use '.' in the file name. it is kind of big Geek NoNO well at least in PC. i dont know how it is with Macs.
Thank u for enlightment.
forgive my spelling.
dont mind anonimity.
"One who is blessed by wisdom, kneels to enlightment." -Anonimous.
By
Anonymous, at 10:58 PM
Actually, whenever you download a file you should be able to rename it on your own machine. For example, let's say you download the file "MTH.121.Quiz.02.key.jpg" to your desktop. You can then rename it "MTH 121 Quiz 02 key.jpg" or whatever else you like. I'd suggest keeping the extension "jpg" or else your OS may not know how to open the file. I believe renaming should work nicely.
As for the "periods" in files names . . . they are there solely to make the URL easy to parse -- the space is not a legal character in a URL. So "dots" or periods are often used, especially by UNIX geeks. You should look at a URL sometimes, although spaces can be used, the space, when used, has to be encoded as a %20.
From "Dan's Web Tips": "Some Web servers might have file systems that allow documents with names containing spaces, but if you use files with such names, their URLs will contain %20, which is rather ugly. So it's best to avoid such names and stick to safer characters like letters, numbers, dashes, and underscores. Mac users in particular tend to create directory structures including spaces, producing awkward URLs."
I hope this helps.
You ended with a philosophical tidbit, and so do I.
By
Ron Bannon, at 6:55 AM
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