In my last question, I asked for algorithms that changed the world. Now I'd like to know, what are the data structures that changed the world? [more inside]
You're an armchair scientist and you like reading scientific papers. A lot of the fun ones include a lot of equations. You'd like to be able to recreate those equations in a virtual blackboard. You'd select terms and be able to replace them with a library of previous equations you've made. The blackboard would enforce whatever symbolic manipulation rules are required to maintain consistency (because you sure won't be able to). If you replace a term with a number or a data input, it does the calculations necessary to display properly. What is it? [more inside]
I have a set of data: D(t). 5000 samples. Scatter-graphing makes some patterns clear (D-mean increases with t, for instance). D and t are always positive. I want to characterize these, statistically. [more inside]
My eldest child is starting high school. She is in the most advanced math class (a version of geometry) offered by her fairly demanding high school. But my eldest is struggling during the review of algebra -- rate problems, word problems, etc. Concerned because math is cumulative, and I don't want her falling behind. What can I do to help, both with math and with preventing her from becoming discouraged? [more inside]
For my son’s high school history class, he has been assigned an in-class argument/opinion essay. The teacher ended most of the lecturing this week and has given them time to prepare thesis statements for the essays. Here is where it starts to get complicated (at least to my son and me): [more inside]
In one of these puzzle games like 2048 or Threes, where you merge tiles to create higher numbers, is there any way to prove what is the highest possible tile number that can be created given the rules and dimensions? [more inside]
I have always been really bad at really simple games, like the ones where there are generally sound mathematical strategies for playing the optimal game. I'd like to compile a little mental rolodex of simple games and their solutions so I can feel smugly superior to any small children who seek to challenge me. [more inside]
What are your favorite iPad apps for 4 - 7 year olds? [more inside]
I'm interested in learning about the details of English grammar and usage, and also maybe in picking up some prescriptions or guidelines for writing well-styled/balanced prose (a la Strunk & White, though my understanding is that there's potentially a great many schools of thought to look at here). The kicker: my academic background is in math and computer science, including the very formal reaches of things like logic, formal languages, etc. Is there any way that this stuff can help me learn that stuff? [more inside]
I'm helping elementary school kids with their math and English homework. I really need math resources and strategies for helping kids with their reading/writing homework. Some are English language learners. [more inside]
I've got a bunch of curves that (I hope) show some common profile over time, although they maybe scaled versions of each other: at any index along in the curve >1, the next point is conditional on all (or some) of the previous. See this greatly simplified example. [more inside]
My 2 year old son loves numbers. He can count by himself well into the 50s and can tell you what number he's looking at to at least as high as 110. As for me, well, numbers and I have never been the best of friends. How can I, a numbers-adverse dad, encourage and nurture his talent? [more inside]
I'm trying to draw a 3D ellipse with a 2.5D graphics engine (Core Animation layers) which allow me to only compose my ellipse with line segments that must be moved into place using rotations and translations. I'm having trouble with the order of operations and can't get it to draw properly. Any graphics gurus or game programmers out there who can help me? [more inside]
I'm trying to compare the compounded losses due to inflation to non-compounded profits. E.g. if inflation makes me lose 3% of an investment each year, what % would I need to profit each year in order to exactly keep up? This is tricky because the profit is not compounded the way inflation is. I'm not looking for an answer to this specific question, but rather, looking for a tool or method to do this kind of math. [more inside]
My teen aged niece has suddenly found a strong interest in statistics. What book would you recommend for a 14 year old who has good, but not advanced, math skills?
With deadline looming, stats consultant has bailed. Simple queries need resolution. Help? I am working on a data graphic that involves statistical calculations about survival rates for startup businesses, correlated with certain tangible and intangible factors. The raw data (about survival/closure/merger outcomes) has already been investigated, and the original researchers (who are awesome) have generated some interesting correlations using univariate regressions and Cox regressions. For my output I am relying on their statistically significant findings, wanting to create comparisons among the univariate coefficients. Not sure my methods are kosher and would appreciate consultation. Avalanche inside. [more inside]
I teach math to high schoolers in the San Francisco Bay Area. I'd like to get them out of the classroom on a field trip to a local math-themed destination. Any suggestions? [more inside]
I've never been very good at either math or at eyeballing things like weight or dimension, but was thinking recently about how to more or less accurately weigh things without using a scale. What good methods are out there to approximate other kinds of measurements? [more inside]
A recent post to the blue proposed a set of equations that changed the word. As a computer professional, I'm curious, which algorithms transformed the world? [more inside]
I'm basically teaching myself how to do pass an PhD economics placement test, and I'm looking for resources to learn these things that aren't books. [more inside]
I have just completed my MSc in mathematics in Europe. I do enjoy math, but I spent my uni years feeling like a autodidact hippie marooned on an island full of Mr and Mrs I-Want-A-Good-Job. My main interests revolve around humanities (literature/history/anthropology) and economics (but not finance), and instead of starting a "stable" well-paying career I dream about something inter-disciplinary. I am very open to earning little money and relocating just to do kind of work that engages those skills. What are some random uses of my degree? [more inside]
4x+y+2z=100, x>y, y>z, x+y+z=j, 3x+z=k, j>k, j+k=100. WolframAlpha can only give me alternative forms or a solution involving 'real and imaginary parts of z'. Is there a solution I can count on my fingers? [more inside]
Non-obvious careers for someone with a B.S. in Applied Mathematics? [more inside]
The best way to pursue my college goals given my situation. [more inside]
Is there a game like Math Rabbit out there, but for calculus? Specifically looking for something with lots of game-interface, not Khan Academy.
If I add 1/100 to 2/100, I get 3/100 or 3%. But if I add one hundred apples, one of which is red, to one hundred apples, two of which are red, I will have 3/200 or 1.5%. I'm very confused now as to what percent milk fat my milk will be if I combine the two types of milk (1% and 2%) together.
Wanting to code. Can't read calculus. Kinda stuck. Help? [more inside]
My son would like to know: Is there more to calculus than functions, examples of functions, various formats for presenting functions, and so on? That is, does calculus have unique to it other tools that are not just variations on functions? [more inside]
Years ago I read John Derbyshire's Prime Obsession: Bernhard Riemann and the Greatest Unsolved Problem in Mathematics and loved it. Now I'm studying formal theory/real analysis and I'm finding it really it interesting, but would like to be able to spend my downtime reading about the background of math and also explains some of the concepts. Thanks!
Working on a personal project, I am running into a number of math problems of the kind described within. I am not a math expert, so I don't know what to call these kinds of problems, so I don't know how to search for information about them. [more inside]
I will be returning to school in the fall to start prerequisite courses for a Physical Therapy program. I don't know math. The last time i took math was in high school, and it was basic geometry. I would like to teach myself primarily, so that i can test into higher classes. The goal is to be able to test into pre-calc, so that i can also qualify for the physics classes as well. Any suggestions? I don't really care about the method. I was thinking about buying a textbook, but i was unsure of which ones to get. Thanks.
So, I’ve been doing a lot of thinking about how to land a career in market research analysis. Below are the steps I’ve laid out for myself. Could you tell me if this is a good game plan to get where I want to go? [more inside]
I'm due in traffic court at 9 am. Help me use math to prove I didn't do it. [more inside]
How many unique ways are there to put X rocks into Y boxes? (Given two different sets of attributes for both the rocks and the boxes.) [more inside]
We have an excessive interest rate on our home. We tried to refi, and the appraisal came in a good $40,000 less than it needed to in order to qualify. So some of our more numerically-talented friends ran some numbers for us in an attempt to find alternative solutions and found a weird discrepancy that makes it appear we owe $15,000 more on the loan than we do... [more inside]
I'm looking for a textual version of a2 + b2 = c2 that is as old as possible, among all the Greek sources. [more inside]
Mathfail: I'm considering supplementing my cat's food with plain meat. I'd like a rough idea of how much it would bump percentage of calories from protein and fat. [more inside]
I think my son, who is on an AP math trajectory in high school, would benefit from getting some familiarity and basic programming skills in the Unix world. I've noticed math depts in some universities include study of these skills in early years. Are there some tutorials we could use in the OS X environment to get a leg up? [more inside]
In studying for my Behavioral Statistics final (it’s a statistics class dealing with psychology research methods) I’ve realized something. I actually kind of enjoy math. As long as I don’t have to memorize formulas (as long as they are right there as I’m going through the work) it’s actually kind of comforting and fun. In fact, every math class I’ve taken in college (I’ve taken two remedial algebras, college algebra, and regular statistics before this class) I’ve enjoyed and made an A in. I’m really struggling about what I want to major in (I’m in psychology but I don’t have it in the gas tank to get a PhD), but I know that a lot of people don’t like math. They don’t get it. I do, so I’ve got something there, right? The only problem is, I don’t know what to do with it. These are the parameters… maybe you can think of something that fits? [more inside]
Can someone please tell me (if you could show calculations, that would be wonderful) what the ratio of ratios would be for these two numbers: a) the volume of the earth compared to that of the solar system and b) the volume of a drop of water compared to that of Mount Everest?
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 = r2 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]
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?
Trying to find an article I read sometime in the last three months about Common Core math. [more inside]
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.
I’ve spent my 20s building a BS “identity” as an “analytical type of person". Help me grow up. Snowflakes inside. [more inside]
I am going to grad school in the fall. Hooray! Problem: I have to take calculus before I start and I am kind of freaking out. [more inside]
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]
Working through Apostol's Calculus Volume I for personal development. Stuck on a proof, again. Can you help? [more inside]
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]
Okay, I'm in NYC and I need a PI related T-Shirt for Pi-Daytomorrow... Anyone know of any stores where I can get one? (It's too late for an online order)