• Mathematician Chat v. 3.999...
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[QUOTE=Cosa8888;47361970]So today I was presented with a little problem: Find x in x^(x-5)=(1/8)^(8-x) I tried solving it with logarithm but apprently x does not exist, is there an answer to this?[/QUOTE] Taking logs and drawing a graph of log_8(x) = (x-8)/(x-5) makes it pretty clear (I think) that there is no real solution. If you're allowing complex numbers, all bets are off.
I've been reading Ravi Vakil's algebraic geometry notes recently and I dreamed about them the other night something is wrong with me
In my darkest moments I couldn't stop dreaming about doing maths or having to answer my antipathetic teacher's questions. Even now, I dream about preparing for exams to enter my uni even though I already passed them.
I have dreams about school all the time, but this is the first time I've had a dream about math by itself.
[QUOTE=Joey90;47363754]Taking logs and drawing a graph of log_8(x) = (x-8)/(x-5) makes it pretty clear (I think) that there is no real solution. If you're allowing complex numbers, all bets are off.[/QUOTE] Wolframalpha gives a numerical solution. Which method does it likely use?
[QUOTE=JohnnyMo1;47364155]I have dreams about school all the time, but this is the first time I've had a dream about math by itself.[/QUOTE] huh, i have that mainly when i am doing some stupid transport problem that uses like 3-4 change of variables and the math gets stupid convoluted, or when i was doing my CME thermodynamics project in excel
So I have to choose between these two classes. I don't really enjoy math as much as I used to so I'm curious to know as to which you guys would consider easier. [b]MATH 125 - Finite Mathematics and Modeling[/b] or [b]MATH 153 - Introduction to Statistical Methods.[/b] [b]MATH 153 - Introduction to Statistical Methods[/b] is 4 credits instead of 3 so I'm guessing it's the more difficult subject?
Those both sound sooo boooorrriinnnng. What is your major?
Accounting.
Ah, no wonder. I'd probably go with finite math and modeling. I'd think it would be more relevant, but then I'm not an accountant. Also, check google today. It's Emmy Noether's birthday!
Please, dear mathlords, help me with my conundrum. In programming for Unity I've run into a strange issue. Can you tell me if this seemingly simple math is completely okay, or if it's some problem in how I'm using my programming language? multiple = 50 grid = floor(testPosition / multiple) distance = abs(testPosition - (grid * multiple)) Grid should represent the nearest multiple to the test value. For example, 110's grid is 2, and 49's is 0. My problem: Inexplicably, distance is [I]sometimes[/I] greater than 50. I don't have a lot of ways to debug the situation to learn more in my situation. It seems to me that it should never be over 50. Here's a picture to explain: [t]http://foxcock.me/web/dump/Phone%20Camera/Camera/IMG_20150323_231148156.jpg[/t] So all I ask, is: is the math fundamentally wrong, or should I consider this an error in my use of the programming?
[QUOTE=bitches;47383583]Please, dear mathlords, help me with my conundrum. In programming for Unity I've run into a strange issue. Can you tell me if this seemingly simple math is completely okay, or if it's some problem in how I'm using my programming language? multiple = 50 grid = floor(testPosition / multiple) distance = abs(testPosition - (grid * multiple)) Grid should represent the nearest multiple to the test value. For example, 110's grid is 2, and 49's is 0. My problem: Inexplicably, distance is [I]sometimes[/I] greater than 50. I don't have a lot of ways to debug the situation to learn more in my situation. It seems to me that it should never be over 50. Here's a picture to explain: [t]http://foxcock.me/web/dump/Phone%20Camera/Camera/IMG_20150323_231148156.jpg[/t] So all I ask, is: is the math fundamentally wrong, or should I consider this an error in my use of the programming?[/QUOTE] It's true that it's never more than 50. You can find an upper bound on distance on [0,50) and then use the fact that it's periodic. Look for an error in the programming. Why don't you have many ways to debug in your situation?
Holy shitstacks, [url=http://stacks.math.columbia.edu/][B]The Stacks Project[/B][/url] is pretty crazy. Almost 5000 pdf pages of collaboratively written algebraic geometry. Pretty well-written too, the sections I looked at. A bit terse, but nothing wrong with that. Like a great big reference book. [url=http://people.fas.harvard.edu/~amathew/cr.html][B]The CRing Project[/B][/url] is similarly cool.
Well while we are at it, there is some webpage that is helping me getting through math college. [url]http://www.teaching.martahidegkuti.com/shared/lnotes/lecturenotes.html[/url] [editline]28th March 2015[/editline] [QUOTE=JohnnyMo1;47389791]Holy shitstacks, [url=http://stacks.math.columbia.edu/][B]The Stacks Project[/B][/url] is pretty crazy. Almost 5000 pdf pages of collaboratively written algebraic geometry. Pretty well-written too, the sections I looked at. A bit terse, but nothing wrong with that. Like a great big reference book. [url=http://people.fas.harvard.edu/~amathew/cr.html][B]The CRing Project[/B][/url] is similarly cool.[/QUOTE] I went through this and damn, this is long.
I posted this in the programming WAYWO [QUOTE=ThePuska;47412614]I haven't studied mathematics for over a year and though I've been doing some basic differential equations and linear algebra every now and then, I can feel my skills slipping away. I got the book "Advanced Engineering Mathematics" by Erwin Kreyszig from a coworker. It's mostly stuff I learned before, but I've been doing the problems just to keep in shape. Does anyone have any good book suggestions for something more advanced? My employer promised to buy them for me. Nobody I know actually studied mathematics so I don't even know what I'd want to learn - I suppose anything.[/QUOTE]
How important is numerical integration for electrical engineers? We had a bunch of snow days so we had to skip that section and I was wondering if I should read up on it or something
[QUOTE=Krinkels;47385279]It's true that it's never more than 50. You can find an upper bound on distance on [0,50) and then use the fact that it's periodic. Look for an error in the programming. Why don't you have many ways to debug in your situation?[/QUOTE] It's a shader, which means I can't print. Debugging is limited to causing visual effects to interpret. [url=http://facepunch.com/showthread.php?t=1260922&p=47412328&viewfull=1#post47412328]more info[/url]
[QUOTE=elitehakor;47412893]How important is numerical integration for electrical engineers? We had a bunch of snow days so we had to skip that section and I was wondering if I should read up on it or something[/QUOTE] I'd say it's pretty important. Integration will help with concept of "energy" or "charge". About numerical integration, well, it's not as hard as you think (it's just for loop and summation in completely basic sense).
[QUOTE=elitehakor;47412893]How important is numerical integration for electrical engineers? We had a bunch of snow days so we had to skip that section and I was wondering if I should read up on it or something[/QUOTE] what i know of electrical engineering is you'll encounter a lot of differential equations, but numerical methods are pretty straight forward and easy enough to learn just by reading up on them, but they can be unstable and oscillate wildly around the true answer [editline]28th March 2015[/editline] also i know electricals use a lot of charts that look crazy
I don't know numerical integration (or in general solving PDE's numerically) can get pretty complex, especially if you start investigating convergence and consistency of discrete schemes. The (simple) Euler method is usually not used because it kinda sucks.
[QUOTE=Number-41;47414261]I don't know numerical integration (or in general solving PDE's numerically) can get pretty complex, especially if you start investigating convergence and consistency of discrete schemes. The (simple) Euler method is usually not used because it kinda sucks.[/QUOTE] mathematically complex, but they're basically a set of step by step operations done itteratively, very easy to impliment in an excel spreadsheet even though the functions are complex, i had a class on the matter and while i had no clue sometimes how or what the actual formulas were doing it generally was like a 3-4 step process, hard as hell to do by hand but easy enough with spreadsheet 1) guess good starting points 2) calculate the next value 3) check bounds 4) re-itterate its very analytical though, because you have to sort of guess good values and understand whats going on in the data, like when something is oscillating or won't converge or passes the true answer. i liked mucking about with numerical methods, but they're not really hard to pickup or change the formulas about when you understand the limits of the method and know how to interpret the results
Hey all. I dropped my calc class because of some things that happened with my transfer agreements, so I have to retake it next semester. I have the entire summer off to work, and plenty of time to study. What's the best book I can use to teach myself calculus, so that the class is easier when I get back next semester?
What is your major?
[QUOTE=JohnnyMo1;47417556]What is your major?[/QUOTE] Cs
[QUOTE=proboardslol;47417600]Cs[/QUOTE] Stewart's [I]Calculus[/I] is standard, but a bit bloated I think. Okay but not great. I prefer Hass, Weir, and Thomas' [I]University Calculus[/I]. My best recommendation would be Spivak's [I]Calculus[/I], but it's more "theory-based," which is probably unnecessary for CS. The other two are how to [I]do[/I] calculus via tons of practice, Spivak is for teaching math majors how calculus really works.
Does anyone have any recommendations of higher level maths resources that don't require a degree in Egyptian hieroglyphic decryption in order to understand? The more recent stuff I've been studying in vector calculus and Computation make no sense to me, as they are only presented in a garbled combination of Nablas and surface integrals. This is specifically talking about the divergent theorem, stoke's and greene's theorem, curl & div and some random stuff about Chebyshev polynomials
IMO if the symbols are unclear you should just see where they come from and brush up on that, i.e. vector calculus. So look for an introduction to Vector Calculus (btw. Griffiths' Electrodynamics has a nice (physically motivated) intro to vector calculus) and get a solid understanding of the symbols and some of their properties.
[QUOTE=Number-41;47423007]IMO if the symbols are unclear you should just see where they come from and brush up on that, i.e. vector calculus. So look for an introduction to Vector Calculus (btw. Griffiths' Electrodynamics has a nice (physically motivated) intro to vector calculus) and get a solid understanding of the symbols and some of their properties.[/QUOTE] Weird, I just picked up Griffiths again yesterday, glanced through chapter 1, and thought, "Hey, this is a good vector calc review! I should work through this chapter." But yes, Griffiths is really good for that
Yeah, if the usual terminology and abbreviations are confusing to you, then a more literal approach would be even worse. I don't know much about the symbols Anglo-Saxons use, but the French terminology can be learned in about five minutes. It also simplifies calculations a lot. Basically Nablas are used to make grad, curl and div calculations simpler and more intuitive in Cartesian coordinates. Nabla is more or less equivalent to the vector [img]http://i.imgur.com/LjdiTAw.png[/img], and its use to represent grad, div and curl helps calculate them using rather simple formulas: [img]http://i.imgur.com/l7uT4qA.png[/img] [img]http://i.imgur.com/QnXaWeJ.png[/img] [img]http://i.imgur.com/0x55iYD.png[/img] As for surface integrals, I don't know how much you know about them so I'm not sure why they are confusing to you.
Hey, so why is it worth learning Geometric algebra and why is it better than Linear algebra? By the way, doing mathematical optimization, stuff is hard.
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