Ask MetaFilter questions tagged with algebra Questions tagged with 'algebra' at Ask MetaFilter. Sun, 15 Dec 2013 14:02:36 -0800 Sun, 15 Dec 2013 14:02:36 -0800 en-us 60 Physics Study Guide For my pal...What is a good physics study guide for: a) 1st semester algebra-based college physics b) lots of solved problems c) <i>without calculus</i>. I remember liking Schaum's in undergrad, but I seem to recall it being calculus based. Thx Hive!,2013:site.253735 Sun, 15 Dec 2013 14:02:36 -0800 algebra college guide physics study j_curiouser Basic Math for Math Majors Hello! I'm a first semester grad student in applied math. I am a non-traditional student in a variety of ways (liberal arts undergrad, working full-time), and while I'm finding that I <em>intellectually</em> understand the concepts I'm learning, execution is being made difficult by my lack of fluency with algebraic manipulation and calculus. So, here's an excellent example. In a problem set this week, we were asked to find the expected value of <a href="">this god-awful density function</a>. (We had to integrate over 0-inf, solve for the constant <em>c</em>, then do another integration to find E(V).) (it's 2/(sqrt(pi)*sqrt(lambda)), if anyone cares).<br> <br> This, no joke, took me 4 hours. At times I found myself just completely frozen about what to do next. I understand stuff like u-substitution and integration by parts, I'm just mindnumbingly slow at it, and I end up psyching myself out. <br> <br> I need to get better and more automatic with this stuff ASAP. What's the best way to do that, relatively quickly? Are there problem banks somewhere I can use? I have some old books, is going through them helpful? Is there a cool iphone game or something?,2013:site.251889 Wed, 13 Nov 2013 14:08:48 -0800 algebra calculus downing street memo 8th grade math tutoring options? Where can we find low cost math tutoring for 8th grade algebra? I've tried some web searches, but have not had much luck. My niece has been having trouble with math - late last school year, I got her a tutor, and the tutor got her through the end of the year with math - hurray! However, the tutor was really expensive, and I'd prefer to not have to do that again! ($40-50/hour, I think.)<br> <br> She's doing online school, and it's a different one (K12, as oppose to Connections). We'll definitely get in touch with the school to see if they have suggestions for tutoring - the last school was completely useless, and kept putting us off, until she almost failed. My mom is her primary caretaker, and cannot do math at that level. My husband and I cannot tutor her either. So family tutoring is out.<br> <br> I did see, and there are some tutors listed for less (mainly college students, which is fine!) but how do you know if they are good or not? <br> <br> Any suggestions welcome. I hesitate to do online tutoring, because her classes are online, and I feel like she's missing something trying to learn her math that way.,2013:site.246063 Mon, 05 Aug 2013 11:33:45 -0800 algebra homeschool resolved tutor needlegrrl Scale my function for a line graph Math-filter: I have a line chart in Google Docs that plots three columns of data over time. Data in the first two columns ranges from 0-1000, but data in the third column ranges from 3-9. I'd like to "scale" Line 3 (maybe this is the wrong word?) to be able to compare its value over the same graph space as Lines 1 and 2. I think what I need to do is create a new, "scaled" column and plot that as Line 3 instead. Thus, in this scaled column, I believe 9 unscaled would be the same as 1000 scaled, and 3 would be the same as 0. Since this is a spreadsheet, I need something in the form y=<em>f</em>(unscaled Column 3 value).<br> <br> That's all I've got, though, after half an hour of trying to remember my algebra, and then another fifteen minutes playing with Wolfram Alpha. Am I on the right track here? What's the function to scale Line 3?,2013:site.242747 Wed, 12 Jun 2013 07:23:15 -0800 algebra charts googledocs math scaling electric_counterpoint Algebra: exotic identity values? [mathfilter] please give me some example algebraic structures that are not commutative, with exotic identity values. I am creating an inventory of example algebraic structures of one operator that feature associativity, commutativity, identity values and all combinations thereof. My table is nearly full but for three entries:<br> <br> - non-associative, non-commutative with different left and right identities<br> <br> - non-associative, non-commutative with both left and right identities, where both identities are equal<br> <br> - associative, non-commutative, with either a left or right identity but not both<br> <br> (For clarity: a left identity is a value 0l such that 0l . x = x for all x, and a right identity is a value 0r such that x . 0r = x for all x. They may not be both present / the same if the structure is not commutative.)<br> <br> <strong>Do you know of example functions in these three categories?</strong>,2013:site.238714 Mon, 08 Apr 2013 01:48:30 -0800 algebra homework math resolved knz Can a transcendental number raised to an algebraic power be algebraic? Can a transcendental number such as pi, be raised to an irrational, but algebraic power resulting in an algebraic solution? Complex solutions would be acceptable. There might be a quick proof here, or there might not be. - Thanks for any help you can offer answering this! (And I promise that this isn't for a class or anything like that!),2013:site.236360 Sat, 02 Mar 2013 06:33:30 -0800 algebra math number numbers resolved theory transcendental ch3cooh Clearly, this proves that I'm stupid I can't seem to wrap my mind around the language of higher level math. Definitions, theorems, and proofs make me fall asleep, but I really do want to understand. Do you know of any good resources that can help me out? Back in high school (Canadian) I was a math whiz. I had no trouble with any of the concepts, including calculus in Gr 12. I can "do the math" and am good at problem solving. However when I got to university and started taking Number Theories, Abstract Algebra, etc., my logic suddenly disappeared on seemingly simple concepts. I've obtained my degree in CS already, somehow memorizing or handwaving my way through on my assignments and exams, but now I actually need to understand higher math for my current job.<br> <br> For example, these are excerpts from one of my textbooks (A Concrete Introduction to Higher Algebra by Lindsay Childs):<br> <br> [on real numbers] "The real numbers form a complete Archimedean ordered field...Archimedean means that for every positive real number r there is a natural number n with n &gt; r."<br> [division theorem] "Given nonnegative integers a &gt; 0 and b, there exist integers q&gt; 0 and r with 0 &lt;= r &lt; a such that b = aq +r<br> <br> I thought I understood real numbers and division until I read these definitions and was also asked to prove them. First of all, my brain have difficulty just parsing out what's written; it's like a foreign language to me. Secondly I never know how to begin when proving things. I can somewhat follow along if there's an example in the textbook, but on my own I would be completely lost.<br> <br> I'm not looking to take any classes in math or hire a tutor. Books or online resources would be good. At minimum I'm hoping to at least be able to read through a math textbook and actually understand the explanation.,2013:site.234391 Thu, 31 Jan 2013 20:35:00 -0800 algebra college higher math proofs theorem university lucia_engel The use of Linear Algebra in Programming. I just finished my first course in Linear Algebra. I know a fair amount of Python. Please help me come up with a project that combines the two. This past Fall semester, I took Linear Algebra I, a 200-level Math class at my school. (The next class, sequentially, is Linear Algebra II -- a 300-level class which is much more proof based.) I don't want to list everything that I learned, but I will say that the course covered a lot of material, and was quite rigorous.<br> <br> Through the lectures, my professor would frequently reference Linear Algebra's application to computer science/computer graphics (e.g. how each pixel in an image can effectively be manipulated as an entry in a matrix). <br> <br> Likewise, I want come up with a project that combines my newly acquired knowledge of Linear Algebra, with my ability to program.<br> <br> A couple of notes with regards to the type of project that I am looking for:<br> <br> 1. I'm not really interested in game design or computer animation (and I know that both are predicated on Linear Algebra).<br> 2. I really like databases. In addition to Python, I know/am learning SQL -- I would love something of the sort that combines matrix manipulation with querying a database (if this is even a thing.)<br> 3. I'm learning Django, so any idea that involves building a (not too complex) web app would be great.<br> <br> Thanks a lot!,2012:site.231710 Sun, 23 Dec 2012 10:46:06 -0800 algebra database linearalgebra math programming lobbyist Algebra Question Can anyone help with an algebra question I am trying to help my neice with her homework. (9/2m) - (m+4)/4m = 5/36<br> <br> 11th grade algebra- do you multiply entire equation by 2m? lowest common denominator? help. An explanation would be great and also any websites that help with algebra would be great too. Thanks.,2012:site.229095 Sat, 17 Nov 2012 11:35:42 -0800 algebra math Summer Fall Need help finding an easy-to-follow Algebra textbook Introductory Algebra Course - book recommendations? I'm now back in university, after being away for 3 years. Hurray! During my first term back (winter term), I need to take an introductory Algebra course in order to meet a prerequisite for an upper-year Psychology research class. The problem is, I haven't taken any Math classes since high school (so well over 5 years) and it has never really been my forte. No doubt it, this course is making me incredibly nervous. To top it off, the textbook required ("<a href="">Mathematics with Applications</a>") for the course is supposedly incredibly hard to follow. I'm a big fan of easy-to-read literature, with lots of thorough examples and test questions; but I admit, the reviews about this text sound like it contains anything but.<br> <br> Here is a gist of what we will cover: linear equations, exponential functions, matrices, system of functions, probability, compound interest.<br> <br> It's a little early, but I'd like to get my hands on a textbook/resource to make me familiar with some of these concepts before I start the actual class. Is there an introductory algebra book that you liked, and would recommend?,2012:site.226347 Tue, 09 Oct 2012 19:33:41 -0800 algebra book course introductory raintree Help her learn Alg II by Tuesday Sister just learned she has to take an Algebra II test on Tuesday that covers the whole shebang. She's forgotten (repressed?) most of it. What's her best bet for an Algebra II crash course that will go over all the topics? She's very smart, but not a math person.,2012:site.223432 Thu, 30 Aug 2012 10:04:47 -0800 algebra math goosechasing My Trig Teachers Name Was Mr. Angle But That Didn't Make Him A Good Teacher. My math skills are no where near where I'd like them to be. Can you recommend a self-paced math learning site? Pretty much any branch of math can apply. Due to some amazingly awful teachers at some key points in my life Math and I have been in a state of cold war for decades. I'd really like for that not to be the case any more.<br> <br> Ideally I'm looking for something like <a href="">Project Euler</a> or <a href="">Ruby Koans</a> are for programming. That is: A site with increasingly difficult concrete problems that need solving, not just naked formulae. Substantially prefer hands on/reading over watching videos/lectures (<a href="">Khan Academy</a> hasn't really resonated with me).<br> <br> As I mentioned pretty much any branch of math is fine. Algebra, trigonometry, calculus, differential equations, statistics, you name it, I'd like to be better at it.<br> <br> High school level and above.,2012:site.222158 Mon, 13 Aug 2012 12:20:53 -0800 algebra calculus math mathematics selflearning trigonometry Ookseer Math is Hard (I need help) Math is hard. Please help me with a slope-related problem. I have a project that is 103 inches high on one end, and 119 inches high on the other end. It is 394 inches long.<br> <br> Given this information, I need an on-line calculator that can tell me the height of a vertical line drawn at any point along the 394 inch length.<br> <br> PS: I know this is probably simple math, but I'm utterly failing at this for hours and hours. If I have to do the actual math problem I will, but I feel at this point that some kind of automatic calculator is going to be the best solution to get me the <i>right</i> answers, especially since I'm going to need to calculate 20 (or more) vertical lines along this distance.<br> <br> Thank you!,2012:site.220566 Sun, 22 Jul 2012 15:49:52 -0800 algebra geometry math mathishard riseoverrun slope trig anastasiav Is it possible to solve for X? <strong>(Y)(S^N) = (M)(X^(N+E)) - (Y)(X^N)</strong> Is it possible to solve for X? I'm working on a manuscript (psychophysics), and it would be nice if I could solve for X in the following equation:<br> <br> (Y)(S^N) = (M)(X^(N+E)) - (Y)(X^N)<strong><br> </strong><br> the damn E term seems to be ruining things. Without it, it's simple enough.<br> <br> My math isn't the greatest, so I could really use some help!<br> <br> thanks!,2012:site.213821 Wed, 25 Apr 2012 14:45:27 -0800 algebra equations math resolved spacediver Mr. Math Monster, I presume? Help me to learn math as an adult when I still despise the frustrating beast from my childhood! Since I was a kid, I’ve always struggled with math. I was apparently very good at it when I was a little girl, grasping concepts that hadn’t been taught to me yet, but somewhere in there I determined I hated math. Or that it was too hard. I even drew up a manifestation of my fear, the Math Monster. With 7’s for spines, 6’s for claws, 5’s for teeth, and extra numbers floating about in its half gelatinous, half dragon form, the creature is STILL what I think of when I even halfway glimpse an equation with x = ?.<br> <br> Now, several years and maybe 2 to 3 college level Algebra classes later, I’m an adult who’s realized that math is actually useful. And pretty much a requirement for life. Especially when my “maybe I could…” interests show me possible life paths involving chemistry, physics, quadratic equations, and theoretical computer science.<br> <br> Look, I know I’m smart, but I just need things explained to me in a way I can visualize. I’ve grasped many algebraic concepts before, but I find it difficult to remember even a few months later how to, let’s say for example, find the percentage for a restaurant tip.<br> <br> Basically, I’m trying to get back into the math groove, and I’m looking for recommendations on textbooks that are neither dull as shit nor pandering like a kid’s picture book. I just want math to be interesting to me. These textbooks should also obviously be as accurate as possible, since I wouldn’t know an error even if it threw me a wet t-shirt party. <br> <br> I note, btw, that I never was able to memorize my multiplication tables and have therefore become a near advanced level wizard at finger tapping to half sing-song tricks such as “5 x 5 = 25, 5 x 6 = THIR-ty” and “9 x 9 = the 49er’s” which flit by so fast now, I barely notice them anymore.<br> Also of possible importance: if geometry were the only mathematical subject of importance, I’d have _that_ beast paraded around on a leash, wearing a tag that says “Snuffles”.<br> <br> SO! More or less I want to review math starting from Algebra, reviewing Geometry, and onward. Can you help?,2012:site.211266 Sat, 24 Mar 2012 04:33:38 -0800 algebra arithmetic geometry mathematics DisreputableDog Online mathematics Which are the best online courses for studying algebra and progressing up to trig, calculus, and differentials? Should I look into places like Khan Academy, MIT Open Courseware, etc? Does a community like Reddit have study groups? What other places should I look and and why? Quality is more important than whether it's free or cheap, and it needs to be something I can do strictly at home. I'd also like to know who offers options for tutoring, grading, assistance, etc. I'm pretty self-motivated and have reasons to learn this stuff.. I just need to know where to go.,2012:site.208575 Sun, 19 Feb 2012 08:39:08 -0800 algebra course mathematics online crapmatic Simple solution This is pretty straightforward algebra/chemistry which is why I'm embarrassed to ask my co-workers to help me so... If I have the dilution ranges of a series of solutions of MSG, how can I figure out, in grams, how much MSG I need in 1L of water to make the stock solution? I get that:<br> <br> x M =y moles/z L <br> <br> Let's say my stock would be 1.0x10(-1)M. And the molar mass of MSG is 169.111g/mol. <br> <br> Given the above:<br> <br> 0.1M (msg) = 0.1moles/1.0 liter <br> <br> and converting moles to grams = 0.1 moles x 169.111g/mol = 16.9g of MSG/L<br> <br> Is that it? Or did I miss some element? It seems too simple but it's been a while.,2012:site.204944 Thu, 05 Jan 2012 12:25:38 -0800 algebra Katine I still KNOW the quadratic equation, just not what it means I have forgotten basically all of math, and I want to learn it again from the ground up. While attempting to prep for the GRE, I realized that I have really lost my entire math background. I was extremely frustrated by trying to do the exercises in my GRE book, because I've forgotten even the little things from, like, 7th grade algebra that I used to take for granted I knew.<br> <br> The thing is, I actually used to be pretty good at math- I did two years of AP Calculus in high school and did, well, ok at it- but I then placed out of college math with my AP scores and never did math again. Now it's been five or six years and I can't so much as add fractions or remember what the purpose of the quadratic equation is. I couldn't even remember the formula for the diameter of a circle until I looked it up, for cripe's sake.<br> <br> This isn't just about prepping for the GRE. As I was struggling with my GRE book, I realized that I actually LIKED math, and I'm sad that I've forgotten it. It's like I forgot a language I used to know, or something. (I <em>thought</em> I didn't like it while I was in school, but that was mostly because I had an hour of math class and an hour of math homework every single day, which burned me out.)<br> <br> SO. I would like to completely reboot my math knowledge, starting with the absolute most basic stuff (like, arithmetic basic) and moving up at my own pace until I can do at least basic calculus again. Ideally I would have access to LOTS of problems with available answers, so that I could spend as much time as I needed on a particular topic. I expect I'll advance through the basic stuff pretty speedily, and then take my time with the more advanced stuff. <br> <br> What is the best resource or resources for this? And have any of you guys ever tried to do this before, after such a gap? How was it?,2011:site.198850 Wed, 19 Oct 2011 08:37:15 -0800 adultlearning algebra calculus geometry learning math mathematics showbiz_liz 1 + 10 + 100 + ... = -1/9 Mathfilter: In Gelfand's exceptional <a href="">Algebra</a> text, he is talking about the formula 1 + x + x^2 + x^3 + ... = 1/(1 - x). He uses the Achilles racing the tortoise model when first introducing the formula. He discusses the case x = 10, whence 1 + 10 + 100 + 1000 + ... = -1/9. Then he says the following: "Is it possible to give a reasonable interpretation of the (absurd) statement 'Achilles will meet the turtle after running -1/9 meters?' (Hint: Yes, it is.) " <br> <br> I have puzzled over this for awhile and am not sure what he had in mind. Does the hive mind have any ideas?,2011:site.191843 Wed, 27 Jul 2011 06:45:57 -0800 Algebra Gelfand geometric infinite resolved series wittgenstein Linear Relationships in Real Life? I am redesigning a high-school Algebra course so as to make it more meaningful to the students. To that extent, I am trying to gather as many examples throughout our world of linear relationships. I was hoping to tap into the collective wisdom of this group to come up with as long a list as possible of linear relationships that actually exist (not contrived stuff). I once knew a teacher who had a plant that grew at a linear rate. I don't know the type of plant, however. And there are so many other linear relationships around us. I don't want everything they see be about a car's distance from home or the amount of money they saved. What do you know of that exhibits a linear relationship? I'd love to have a long list for students so that they see that studying linear relationships in Algebra really does matter. Thanks for any help in making this course more worth while to the students!,2011:site.191311 Thu, 21 Jul 2011 05:06:40 -0800 algebra correlation education linear math mathmatters If an geeky child is traveling South at 839 MPH, and his nerdy dad is going North at... My son, who is finishing up third grade, loves math and especially the basic Algebra he's been doing. He is actually sad to be leaving school for the summer because he's so into it. How can I keep this going for him over the summer? Fun books, board games, computer (on-line and OSX) games? Seriously, Jason Fox is this kid's idol. He desperately wants to learn Calculus, though I don't think he even knows what that is. For now he's happy doing algebra such as "2x + 5 = -7 + 10x" (Those are just random letters and numbers. I have not checked if that's a legit equation. I spent my summers avoiding math, you see)<br> <br> He's finishing up 3rd grade at a Montessori school, ready to go into forth, or "Upper El" as they call it. While I want him to have the usual summer of playing Minecraft, chucking rocks at beehives, and frolicking merrily outside I'd like to keep him entertained with whatever math he's willing to do.<br> <br> So what can I give him? While computer games are fun I would prefer non-computer things if they exist. Interesting books (not just books of random problems), board games, TV-shows, YouTube videos, activities, etc. I'm happy to know about any computer games as well. We're Mac people, at least at home. Really anything that will engage him and help him to <em>understand</em> the math he's doing.<br> <br> He is a nine year old, and while he's advanced in math for his age he is still a kid, so anything should be somewhat age appropriate.<br> <br> Everything I give him will be optional for him over the summer, of course. I'm not interested in pushing him where he doesn't want to go.,2011:site.187878 Wed, 08 Jun 2011 10:43:33 -0800 algebra chuckingrocksatbeehives kids math maths school summervacation bondcliff CS Math books I am a GIS college student looking to develop my skills in programming, particularly in Python. For starters, I need to wake up my dormant math skills. What mathematics-for-programmers books, or general Computer Science books, should I be looking for? Hey all, longtime mefi reader (lurker?) , first time poster.<br> <br> Anyway, I am a college student in the midwest USA currently working in the GIS department for a decent sized city. My internship and my college curriculum have made me aware that I need to develop my skills on the scripting side of things. <br> <br> That being said, I don't want to go with a narrow approach and read nothing but "Python for GIS" type articles. I have learned the hard way way that if you try to skip the foundational skills when trying to learn something technical, it just comes back to haunt you down the road. I am not trying to transition from GIS tech to full fledged Computer Scientist but I am an avid learner and want to strengthen my skills.<br> <br> I have not had a huge problem so far finding books on learning Python. I have just started going through <a href="">Python for beginners</a>, and am liking it so far. I've also just ordered John Zelle's <a href="">intro to CS using Python</a>. I'm having a harder time finding general into to CS books and math books relating to programming, specifically on the subjects of discrete and algebra. My school library has a lot of resources, and I've found a few good books, but mostly I'm just overwhelmed by the sheer amount of material.<br> <br> Many years ago when I first started college I did well in my algebra and pre-cal classes, but I'm feeling rusty. And regarding the CS stuff, some of the programming books I'm looking at are using phrases like "garbage collection" without any explanation. I understand the general idea of garbage collection but a paragraph or two would be nice. I don't need the concept of a CPU explained to me, but a book with a little elaboration on CS vocabulary would be helpful.<br> <br> I should probably say that I'm not looking for something like Knuth's <a href="">Concrete Mathematics</a> . I browsed through it at my school's library- I was able to understand bits and pieces, but the rest might as well have been written in hieroglyphics. Many of the books in <a href="">this thread</a> seemed to be above what I'm looking for as well, but I found some of the recommendations useful.<br> <br> I've found some good online resources like MIT's open courseware, but I'd like to have some good textbooks. Thanks in advance.,2011:site.183111 Sun, 10 Apr 2011 17:40:18 -0800 algebra computerscience GIS mathematics programming ajax287 "New" math? Multiple students taking an exam at different times come up with the same baffling answer. Help! Creative minds, please apply.<br> <br> Easy enough college-algebra level question on an exam. The students were asked to compute log<sub>3</sub> 81. Of course, the answer is 4. <br> <br> At least 4 different people answered something strange. Three get 38.65, one gets 38.64 (as if there is some rounding involved). None of them show any work. I'm trying desperately to figure out what they were thinking (or what they may have been typing into a calculator). These students could not have been cheating off each other. Any ideas?,2011:site.181330 Mon, 21 Mar 2011 10:40:24 -0800 algebra batshitinsane logarithm math resolved strangeanswers King Bee How to manipulate "12 = x - (square root of x)" into "x=" The solution to 12 = x - (square root of x) is 16, but how do I manipulate the equation to show that? I've been tiring myself out trying to manipulate this equation down to an "x =" form for too long, so I thought I'd try opening this up to the hive mind. <br> <br> My first thought was that you could simply square both sides, but that leaves you with 144 = (x-sqrtx)(x-sqrtx) x^2 - 2*x^1.5 + x (not so helpful.) This is a frustrating problem for me because it's so obvious that it equals 16, but I can't make the math say so. <br> <br> (I apologize in advance if the idiocy of this question offends all of the math majors and Ph.D. candidates that hang around here. I haven't taken a math class in a long time.),2011:site.179252 Wed, 23 Feb 2011 20:56:34 -0800 algebra equation math Wanderboy Equality Now! BBall Substitutions dilemma MathStoryProblem: I coach youth bball and need help with equal playing time substitutions with a line-up that varies week to week. I think some kind of formula or counting trick should help, but my math skills are failing me. Up to 15 kids, 10 substitutions per game (25 min halves - subs every 5 min). As close to equal amount of floor time as possible (obviously, this can't always be the case). Is there a way to make this functional? Printing a few pages of roster i can fill in when the game starts so i don't have to do subs all game instead of coaching (yelling futile encouragement)? I never know how many kids will be there until tip-off. Embarrassingly, I have very little basketball knowledge but the local Salvation Army needed some help and what the hell, right? The kids are 7 or 8 and very very aware of who gets how much playing time.,2011:site.179219 Wed, 23 Feb 2011 14:11:03 -0800 algebra basketball storyproblem substitutions youthbasketball ten year lurk