Why are the letters 'h' and 'k' often used to represent the center of a circle in the standard equation of a circle:
(x - h)2
+ (y - k)2
are 'h' and 'k' short for something? I might guess 'h' is short for 'horizontal', but I can't imagine what 'k' is for. [more inside]
posted by Reverend John
on Apr 17, 2014 -
I work as a math tutor at a community college and have the opportunity to spend an hour teaching math to a group of students preparing for a the college's math placement test. Now, I don't know what's on the placement test, but I want to teach something that's more engaging and conceptually accessible than "here's how to multiply (4x+3)(2x+5)", since I can't possibly review all of high-school math in an hour and don't think the students will get much from just another lecture. What are some interesting topics that I can explore that will be accessible and memorable?
posted by LSK
on Apr 10, 2014 -
For professional and academic reasons, I need to take a number of college-level math classes (mainly Calculus and Linear Algebra) in a relatively short period of time (4-6 months). They need to be online, for-credit, and I need to be able to do them at my own pace, meaning faster than a normal 1-course-per-semester flow. I've already found https://netmath.illinois.edu/
, but the classes are terribly expensive, so I'd like to learn of other alternatives that don't cost as much.
posted by dcrocha
on Apr 4, 2014 -
I’ve spent my 20s building a BS “identity” as an “analytical type of person". Help me grow up. Snowflakes inside. [more inside]
posted by anonymous
on Mar 29, 2014 -
Can/how can one improve the estimate for a chance of an event with a small historical sample size by utilizing the chance of a related event with a large historical sample size? Example and half-assed guess inside. [more inside]
posted by Flunkie
on Mar 20, 2014 -
Working through Apostol's Calculus Volume I for personal development. Stuck on a proof, again. Can you help? [more inside]
posted by bfranklin
on Mar 18, 2014 -
What is the best way to take grad level notes that feature tons of text, math equations and diagrams, during class, while reading books, and while reading research?
Ability to search and organize a huge plus!
Digital or non-digital solutions considered. [more inside]
posted by Riton
on Mar 18, 2014 -
Okay, I'm in NYC and I need a PI related T-Shirt for Pi-Day
tomorrow... Anyone know of any stores where I can get one? (It's too late for an online order)
posted by Stu-Pendous
on Mar 13, 2014 -
Why do we have order of operations rules in arithmetic instead of just strictly evaluating expressions from left to right (possibly with parenthesis for grouping if we really wanted to change the order)?
posted by Reverend John
on Mar 11, 2014 -
My ignorance of science and engineering concepts, procedures, and methods of calculation is holding me back from tackling a whole mess of fun stuff. But what fields am I even interested in, and how can I learn more? Where do I begin? [more inside]
posted by rue72
on Mar 4, 2014 -
Which mathematicians write exceptionally well or exceptionally clearly? (Individual books or articles would also be acceptable.) [more inside]
posted by hoyland
on Feb 28, 2014 -
I have $800 for tuition reimbursement, and would like to take a linear algebra online course this summer. It doesn't matter if its for credit or not. Thanks!
posted by MisantropicPainforest
on Feb 23, 2014 -
What are some of the newest methods being used these days to teach young children arithmetic? [more inside]
posted by Dansaman
on Feb 10, 2014 -
I'm trying to help my 3rd grader with his math homework, but we are stuck on one problem. I can solve it using Algebra, but I'm trying to figure out how to explain it to him using the Singapore method
that he's taught in school. Note that he hasn't learned how to add negative numbers, which puts a crimp on the methodology. [more inside]
posted by agog
on Jan 27, 2014 -
Working through Apostol's Calculus Volume I for personal development. Stuck on a proof. Can you help? [more inside]
posted by bfranklin
on Jan 25, 2014 -
Have a look here
. I'm assured that differentiating 1, with respect to x
, gets you 2. Now 2 is - I think, and correct me if I'm wrong - equivalent to 3. The problem is I can't see how 3 is the result of differentiating 1. What's more, an online solver produces something (that looks) very different
. Can someone help me out?
posted by ed\26h
on Jan 17, 2014 -
I've been asked at work to come up with a list of topics that could be included in a training course around basic maths for business people, and I am finding it hard to find suggestions for topics. [more inside]
posted by StephenF
on Jan 14, 2014 -
A coin flips three times and comes up heads 2/3. Not suspect.
But a coin flips 100,000 times and comes up heads 2 out of 3 times, that starts to look fishy. The standard probability of this is always roughly 50-50, but assuming a 2/3 ratio pointing to a "rigged" coin, how could you plot the increasing likelihood that a given coin is rigged? [more inside]
posted by ASoze
on Jan 8, 2014 -
I have a question about probability math. I am essentially flipping a coin (except instead of a 50/50 chance, my odds are 50.5% heads, 49.5% tails).
I am concerned with the probability of me hitting heads (a 50.5% chance) several times in a row. [more inside]
posted by disillusioned
on Dec 25, 2013 -
I'm taking a numerical methods class and there are all these discretization schemes of partial differential equations named after pairs of dudes and they all are kinda the same, maybe a bit different in indexes....
I'm trying to organize it all in my head, like a frat house, with the dudes that worked on the same scheme being roommates, but it seems to be taking a long time to actually "find" a place for each scheme in their "rooms" and keeping it there in a sort of visual arrangement.
Test is no books no notes, and everything kinda of just jumbles inside my head right now.
posted by spacefire
on Dec 11, 2013 -
I am going into my last semester of college, and I have signed up to take Calculus III, three years after taking Calc II. This may be a great idea or a terrible one. [more inside]
posted by DRoll
on Dec 2, 2013 -
My son is a junior physics/math major at a small midwestern state university. He needs to start looking at graduate programs. He would prefer to stay in research or academia. How can I help him start this process? (B.S. for me) Location is not an issue. It's more a question of what programs offer the best opportunities and fields of study. How can we find out that kind of information? How can I help him start with a reasonable number of candidates?
posted by DaddyNewt
on Nov 27, 2013 -
I have to take a math placement test in the next two weeks that will determine which college class I will place into next semester (January). I have already taken Math 1010 (Intermediate Algebra) and 1030 (Quantitative Reasoning) long ago but those credits do not count any longer towards this current placement. I need to test to see where I fall now. I'm hoping to get into Math 1050 (College Algebra) ideally. My skills are rusty though. [more inside]
posted by rabu
on Nov 26, 2013 -
I work in a University managing the broad based direct mail, email and calling programs. I have zero undergrad or graduate experience with math, business or the social sciences. (Aka, I can write a really nice essay...) I would like to chart a path to being recognized as an expert in predictive analytics. [more inside]
posted by meta x zen
on Nov 26, 2013 -
I like math. Programming is OK, but I don't want to make it my thing. What careers should I be looking at? (Special snowflake details inside.) [more inside]
posted by sqrtofpi
on Nov 25, 2013 -
Physics geeks! Help me save energy! How do I estimate how much less energy will be used by light siding vs gray siding, based on an experiment with small boxes? I made some identical boxes, put them in the sun, measured temperatures, and am trying to figure out how to scale up. The net has info about different roof colors, but not siding colors. [more inside]
posted by amtho
on Nov 19, 2013 -
Hi, my last questions have been about learning French, then skiing in France (thank you for all those answers to those questions)...and now I'm thinking "what about working in France"? [more inside]
posted by bquarters
on Nov 18, 2013 -
I'm a 45 year-old adult who has just been diagnosed with Asperger's Syndrome. At least, my counselor and my ex- both believe I have it. I don't believe I can be an Aspie because I am *phenomenally bad* with *both* computers *and* math (details on request). Are there Aspies like me?
posted by dr. zoom
on Nov 14, 2013 -
Each card in a certain deck has three letters on it.
The first letter is either A, B, or C.
The second letter is either D, E, F, or G.
The third letter is either H, I, J, K, or L.
Every possible combination is represented exactly once in the deck. Ergo, there are 3x4x5=60 cards in the deck.
How can I determine the probability that a hand of X cards, drawn randomly from the deck, will include at least one of each of the letters?
posted by CustooFintel
on Nov 2, 2013 -
My girlfriend is applying for to work for the city as a crime lab trainee, a position they will train her for, but will be tested for basic knowledge (they are looking for someone with a two-year degree, apparently in anything). The test will include math. What do you think she will need to be sure she's solid on? [more inside]
posted by Bunny Ultramod
on Nov 1, 2013 -
I am a frequent buyer of <$5 books on Amazon. Lately I am interested in math treatises but have been unable to find any that aren't way out of my price range. Am I being way too demanding? [more inside]
posted by myitkyina
on Oct 20, 2013 -
How do you describe the basic concepts of a difficult subject you know a lot about that makes it "click" for a beginner? [more inside]
posted by reenum
on Oct 11, 2013 -
Around 1995 I played a game on the Mac in school that was for educational purposes, supposedly for the purposes of drilling math skills, and had Mozart Symphony no. 40 (1st movement and but I think 3rd as well), Bach BWV 999, and possibly some Paganini as well, as background music. Do you know what it was?
posted by Busoni
on Oct 10, 2013 -
I'm giving a public talk about Goldbach's Conjecture
. There is a crazy Spanish movie
in which a character is famous for having proved the conjecture. Can I show a clip or two from this movie in my public talk? The talk will be in a bar, and there's a $5 suggested donation, so I don't know if that counts as charging people (if that affects the legality of my idea). Thanks!
posted by middlethird
on Sep 26, 2013 -
What is the modern equivalent of 1995's lovely LOGICAL JOURNEY OF THE ZOOMBINIS computer games? They taught math logic skills rather neatly for children, but I don't have a computer that will run the old games.
posted by musofire
on Sep 25, 2013 -
Wizards of Hive,
Before I buy that 90" couch from a friend, how can I make sure I'll be able to get it up my L-shaped stairs? Sure, there are a lot of variables. But is there a tool or methodology for figuring this out ahead of time (presuming I know the depth and height of the couch too)? I don't think I have the cardboard to build a mockup.
This couch is 50 miles away and can't be returned. Thanks!
posted by baseballpajamas
on Aug 21, 2013 -
"Math for Smarty Pants" was awesome -- recommend me more books like that for a kid who loves math puzzles. [more inside]
posted by selfmedicating
on Aug 7, 2013 -
I often find myself crossing interdisciplinary lines and reading research papers, trying to understand some new practice or algorithm in math or computer science. I start out thinking "I just need to understand these basic concepts and I'll crack this", but end up with a very tired brain at 5am, having tried to mainline dense trees of Wikipedia and
Wolfram MathWorld, and still not feeling like I retained everything. [more inside]
posted by hanoixan
on Aug 1, 2013 -
How do you rejig the formula for CAGR to get the starting value when you know the other variables? [more inside]
posted by MuffinMan
on Aug 1, 2013 -
I'm drawing/painting a globe (in time lapse, so the sun appears to rise) and trying to figure out what shape, exactly, the longitude (not latitude) lines are when a globe is flattened into a circle (I know I can just trace them, but I've gotten curious). So, the outermost longitude lines are tangent to the circle, they are half-circles, and the centermost line is a straight line from pole to pole, it's the progressively flatter curves in between that I'm trying to figure out. Do they have a name? Are they catenaries? Are they the curves of progressively larger circles? How do I construct them (easily)? Example image: HERE
posted by sexyrobot
on Jul 26, 2013 -
I'm taking Calc I this fall. I can borrow a graphing calculator for actual exams, but don't want to actually purchase one for day-to-day--or haul it around with me. I have an iPhone and a Nexus 7. Is there a graphing calculator app in one or the other app store that is clearly superior? I'm willing to pay, but under $10, ideally.
posted by Sequence
on Jul 25, 2013 -
I'm taking a standardized test on Wednesday with the Government of Canada and they ask individuals four types of questions. The type that I struggle with are the arithmetic problems... specifically determining the formulas to solve word problems
. I was hoping someone might be able to point me in the direction of a website or easily accessible textbook to practice today and tomorrow before the test. [more inside]
posted by DorothySmith
on Jul 15, 2013 -
Summer vacations are coming up and I am going to use some of my free time to learn physics and math, subjects that I love. In order to do that i asked collegeconfidential.com if anyone had "exclusive study materials" from their university which they could share. I mentioned that I would like to have acess to tests and exams from other universities and I could give some good materials collected by my colleagues of the physics and math course in exchange. [more inside]
posted by tsuwal
on Jul 12, 2013 -