McGill Bill Posted May 24, 2005 Share Posted May 24, 2005 Actually, the limit as B -> 0 of B/2B is half of B/B as B -> 0...is 1/2. It doesn't diverge to infinity because, to put it colloquially, the B's cancel. The cancellation of terms between numerator and denominator doesn't suddenly stop at 0. Or if you want to get fancy, take the derivitave of x/x with respect to x: (d/dx)(x/x) = 1/x - (x/x^2) = 1/x - 1/x = 0. That says the slope of the curve is zero - it's flat. Which means evaluating the equation (x/x) at any point a gives you the same value as at any point b...ergo, if b is non-zero, b/b is 1, and a/a = b/b = 1 even if a is zero. QED. And that's no "subtract the current time from twice the current time, and you get the current time!" mathematical trick. That's straightforward Calc 101. 343693[/snapback] What I was referring to was not that you're taking the limit of B/(2B), but rather the limits of B/y and (2B)/y as y approaches 0, which ARE infinity. Degrees or not, that's the case. Link to comment Share on other sites More sharing options...
McGill Bill Posted May 24, 2005 Share Posted May 24, 2005 what do you do for a living bill? You are fairly well versed in math...i used to know quite a bit (i was a math major for a brief time in school, but eventually got sick of the proofs and abstract stuff, and settled on the math minor), but you seem to have got your sh-- together... 343677[/snapback] I'm actually a student at McGill University in Montreal. Like you, my minor is in Mathematics, and I'm sort of "in the zone" because I'm taking Calc 3 for the month of May. Talk to me in August and I can't count my toes. Where did you go to school? Link to comment Share on other sites More sharing options...
McGill Bill Posted May 24, 2005 Share Posted May 24, 2005 Hey, the calculus proof is a HARD proof, not just crap. It'll stand up to any criticism you want to throw at it. Degrees in astronomy and physics, m'boy...I'm not the world's greatest mathematician, but I ain't no slouch, either... 343699[/snapback] Now if you wanted to get REALLY technical you could use the epsilon-delta definition. Still remember that one? Link to comment Share on other sites More sharing options...
Ramius Posted May 24, 2005 Share Posted May 24, 2005 I'm actually a student at McGill University in Montreal. Like you, my minor is in Mathematics, and I'm sort of "in the zone" because I'm taking Calc 3 for the month of May. Talk to me in August and I can't count my toes. Where did you go to school? 343815[/snapback] Graduated Clarkson U. in '03, so i wasnt too far from where you are...there were many nights we made the 2-hr trip up to montreal...you guys have a fine selection of clubs and "establishments" Link to comment Share on other sites More sharing options...
TheMadCap Posted May 24, 2005 Share Posted May 24, 2005 This is also pretty cool for us scientific types. The number 41 is the largest prime number that begins a quadratic sequence consisting of other primes. Like this: Begin at the number 41 Add 2 to it to get 43 Add 4 to get to 47 Add 6 to get to 53 Add 8 to get to 61 and so on until you get to the fortieth number in the sequence, 1,601. Every number is a prime. Pretty cool. The sequence can be generated by a quadratic equation, hence the name. Consider: f(N) = N^2 – N + 41, where N is any integer between 0 and 40. Even cooler, consider the following: F(N) = N^2 – 81N +1681, where N is any integer between 1 and 80. This starts at the tail of the previous equation [ f(1) = 1,601 ], then proceeds through the sequence in descending order. It reversed direction at f(40) = f (41) = 41, then generates the array in increasing order again! Anyone know if this has a name? Link to comment Share on other sites More sharing options...
/dev/null Posted May 24, 2005 Share Posted May 24, 2005 This is also pretty cool for us scientific types. The number 41 is the largest prime number that begins a quadratic sequence consisting of other primes. Like this: Begin at the number 41 Add 2 to it to get 43 Add 4 to get to 47 Add 6 to get to 53 Add 8 to get to 61 and so on until you get to the fortieth number in the sequence, 1,601. Every number is a prime. Pretty cool. The sequence can be generated by a quadratic equation, hence the name. Consider: f(N) = N^2 – N + 41, where N is any integer between 0 and 40. Even cooler, consider the following: F(N) = N^2 – 81N +1681, where N is any integer between 1 and 80. This starts at the tail of the previous equation [ f(1) = 1,601 ], then proceeds through the sequence in descending order. It reversed direction at f(40) = f (41) = 41, then generates the array in increasing order again! Anyone know if this has a name? 343846[/snapback] i dunno what its called. but i hope it was calculated with a computer. because if any person did that, they have WAY to much spare time Link to comment Share on other sites More sharing options...
McGill Bill Posted May 24, 2005 Share Posted May 24, 2005 Graduated Clarkson U. in '03, so i wasnt too far from where you are...there were many nights we made the 2-hr trip up to montreal...you guys have a fine selection of clubs and "establishments" 343845[/snapback] Hehe, yes indeed, the nightlife, with its low drinking age is quite the pull factor for many students. Did you have any favourite bars? Or can you not remember? Link to comment Share on other sites More sharing options...
Crap Throwing Monkey Posted May 24, 2005 Share Posted May 24, 2005 What I was referring to was not that you're taking the limit of B/(2B), but rather the limits of B/y and (2B)/y as y approaches 0, which ARE infinity. Degrees or not, that's the case. 343813[/snapback] Yes, that is true...but that's not what I meant. I blame the inherent problems in communicating math in ASCII text on a message board... Link to comment Share on other sites More sharing options...
McGill Bill Posted May 24, 2005 Share Posted May 24, 2005 Yes, that is true...but that's not what I meant. I blame the inherent problems in communicating math in ASCII text on a message board... 343861[/snapback] Yes, ASCII doesn't quite work for math discussions. If you think our misunderstanding was bad, here's an answer (which must be submitted in ASCII) to one of the questions on an assignment I have on partial derivatives: -112xye^(-8(x^2)-6(y^2)) - (80+224xy)e^(-8(x^2)-6(y^2)) - (80x + 112(x^2)y)(-16x)e^(-8(x^2)-6(y^2)) Confusing, eh? Link to comment Share on other sites More sharing options...
Crap Throwing Monkey Posted May 24, 2005 Share Posted May 24, 2005 Yes, ASCII doesn't quite work for math discussions. If you think our misunderstanding was bad, here's an answer (which must be submitted in ASCII) to one of the questions on an assignment I have on partial derivatives: -112xye^(-8(x^2)-6(y^2)) - (80+224xy)e^(-8(x^2)-6(y^2)) - (80x + 112(x^2)y)(-16x)e^(-8(x^2)-6(y^2)) Confusing, eh? 343897[/snapback] Ever use the LaTeX formatting spec? Way back before WYSIWIG word processors (e.g. Acrobat), you used to have to use that for submitting papers to journals. I used it once. Once. Makes ASCII-typed math look easy. Even so...that is one nasty equation. It makes me not miss college. What psychopathic professor is requiring stuff be typed out like that? He could at least offer the option of RTF...better yet, download one of the multitude of equation editors out there... Link to comment Share on other sites More sharing options...
McGill Bill Posted May 25, 2005 Share Posted May 25, 2005 Ever use the LaTeX formatting spec? Way back before WYSIWIG word processors (e.g. Acrobat), you used to have to use that for submitting papers to journals. I used it once. Once. Makes ASCII-typed math look easy. Even so...that is one nasty equation. It makes me not miss college. What psychopathic professor is requiring stuff be typed out like that? He could at least offer the option of RTF...better yet, download one of the multitude of equation editors out there... 343909[/snapback] There is an option called "visualize answer" in which, after entering our answer in ASCII, shows what it would look like normally. But you still have to enter it first manually. I've never heard of LaTeX though. Perhaps I should suggest it to the math department though. Link to comment Share on other sites More sharing options...
Nanker Posted May 25, 2005 Share Posted May 25, 2005 Write down your 2004 total income. Multiply it by one. Send me a check for that amount. Oh. Keep the change. Link to comment Share on other sites More sharing options...
JimBob2232 Posted May 25, 2005 Share Posted May 25, 2005 Hehe, yes indeed, the nightlife, with its low drinking age is quite the pull factor for many students. Did you have any favourite bars? Or can you not remember? As another recent clarkson alum...The Dome was where it was at! Link to comment Share on other sites More sharing options...
Crap Throwing Monkey Posted May 25, 2005 Share Posted May 25, 2005 Perhaps I should suggest it to the math department though. 343913[/snapback] You're kidding, right? Tell me you're kidding... There's probably freeware out there that supports it (I KNOW LaTeX apps exist for Linux, at least). Problem is, it's old, awkward, and no longer the standard. It's biggest benefit was that when ASCII text editors were the state of the art it allowed researchers to submit articles in ASCII text format using a common standard. Nowadays, they use Word, WordPerfect, or Acrobat. You can probably find the entire LaTeX standard on the web, but I warn you: it's crap. It's the single biggest cause of mental illness in scientists... Link to comment Share on other sites More sharing options...
Pete Posted May 25, 2005 Share Posted May 25, 2005 "lighten up Francis" 343395[/snapback] you must mean "lighten up Thomas" Link to comment Share on other sites More sharing options...
Tcali Posted May 25, 2005 Share Posted May 25, 2005 Here is a math trick that will stump you. 1. Grab a calculator. (It will be easier than doing it in your head) 2. Key in the first three digits of your phone number (NOT the area code) 3. Multiply by 80 4. Add 1 5. Multiply by 250 6. Add the last 4 digits of your phone number 7. Add the last 4 digits of your phone number again. 8. Subtract 250 9. Divide number by 2 Do you recognize the answer? 343254[/snapback] wellll....#s 4,56,7,8,9 just cancel eachother out--thats fluff...so if yer # is 777 u r multiplying it by 20000--so you get 777,oooo(x2)..u then add lets say 4444(ur last 4 digits) twice..but then u divide them by two again so u just get the same # - adding 1 before you multiplied by 250 earliuer...and then sutracting the 250(#8) just cancels out the 250...so tada--u get the same ## 777-4444. Its a pretty good trick. Link to comment Share on other sites More sharing options...
SHOUTBOX MONSTER! Posted May 25, 2005 Share Posted May 25, 2005 Anyone ever notice that calculators are bills fans too? All you have to do is punch in 2885903, multiply by 2 and turn it upside down. Link to comment Share on other sites More sharing options...
McGill Bill Posted May 25, 2005 Share Posted May 25, 2005 As another recent clarkson alum...The Dome was where it was at! 343927[/snapback] You're joking. You must be. My sweet lord. Le Dome has got to be the single worst place to spend your night in North America. It's really just a bunch of 32-year-olds pretending to be 25 hitting on 16-year-olds pretending to be 20. I went there during frosh week and promised myself I'd never return. It's gross, man. Link to comment Share on other sites More sharing options...
McGill Bill Posted May 25, 2005 Share Posted May 25, 2005 You're kidding, right? Tell me you're kidding... There's probably freeware out there that supports it (I KNOW LaTeX apps exist for Linux, at least). Problem is, it's old, awkward, and no longer the standard. It's biggest benefit was that when ASCII text editors were the state of the art it allowed researchers to submit articles in ASCII text format using a common standard. Nowadays, they use Word, WordPerfect, or Acrobat. You can probably find the entire LaTeX standard on the web, but I warn you: it's crap. It's the single biggest cause of mental illness in scientists... 343977[/snapback] All right, then in that case I suppose I won't suggest it. Instead, I'll petition the administration to force the department to provide free copies of Maple to all students in the Faculty of Science. Link to comment Share on other sites More sharing options...
Pete Posted May 25, 2005 Share Posted May 25, 2005 Anyone ever notice that calculators are bills fans too? All you have to do is punch in 2885903, multiply by 2 and turn it upside down. 344047[/snapback] Link to comment Share on other sites More sharing options...
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