# Tagged Questions

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### Are variables the same in pure mathematics??? [closed]

my question is In pure mathematics, $x$ always $=x$ $x = x$, the variables are abstract. In modelling, $t$ could mean the time that has elapsed since you started a machine for example. Or ...
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### divide amount spent equally

Me and my friend needs to divide the amount spent equally. He brought food worth of 20 dollars and I brought worth of 130 dollars. Now I need to divide this money equally so that we both spend equal ...
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### How many bit strings of length 15 have exactly three 0s?

I need help with this question: How many bit strings of length 15 have exactly three 0s?
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### Pre requisites of linear algebra

I want to learn abstract linear algebra. Do I require the knowledge of discrete mathematics before I start? I have the impression that abstract maths and their proofs can be understood easily by the ...
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### Max(x,y) and argmax(x,y)

I am writing my report and I got confused on this simple maths concept. What I need is: I have 2 values i.e x and y and I want to use the maximum of either x or y as my length. So which statement is ...
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### How to deduce this puzzle

Every station on the railway system sells tickets to every other station. Some new stations were added. 46 sets of additional sets of tickets were required. How many new stations have been added? How ...
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### Different fields of work in different fields of mathematics?

I'd like to get some insight into what sorts of jobs one can expect from the different branches of mathematics degrees. The B.sc. degrees I am familiar with are: Pure mathematics. Applied ...
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### which one? permutation or combination?

Let say we have a bookshelf that can fit 6 books, we want 4 computer science books and 2 physics books but computer books should be together and physics books also should be together, we have 8 ...
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### MOOCs for college-level discrete math?

Specifically I am looking for short lectures (and quizzes) on specific topics. (like Khan Academy offers) Topics I am learning about include; Intro logic-theory + set-theory Notation, negation, ...
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### How and what to teach on a first year elementary number theory course?

In the late 80’s and early 90’s there was the idea of ‘calculus reform’ and some emphasis and syllabus changed. The order of doing things in calculus also changed with the advantage of technology. ...
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### Study regimen for discrete mathematics? - Lack high-school maths…

I have just gotten into college, and will be studying mathematics from next semester. (this course) Unfortunately I did not study mathematics for the last 2-3 years of high-school mathematics. What ...
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### Largest prime factor of 600851475143 [duplicate]

I'm trying to use a program to find the largest prime factor of 600851475143. This is for Project Euler here: http://projecteuler.net/problem=3 I first attempted this with the code that goes through ...
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### how can i solve sigmoid function?

$$\frac{1}{ 1-e^ {-(-3.0)}} = -0.052$$ $-0.052$ is the answer. This equation is sigmoid function. How could I get the answer like that? Please understand me T.T
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### Sum of digits and product of digits is equal (3 digit number)

My child got a question in school (grade) that is: Find biggest and smallest 3 digits number, which has sum of it's digits equal to product of those digits. Help please since I cannot explain my ...
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### Expanding squares and simplification of equations

as i'm reading a paper "An Underdetermined Linear System for GPS" By Dan Kalman i understand the paper but when i traced the equations there's something i don't understand ,may be my mathematics is ...
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### Starting my nephew out on the journey to higher mathematics.

My nephew is 8 years old and shows great promise as a student. Sadly, as most of you know most programs in secondary education don't offer any foundational courses for higher mathematics. What ...
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### Good discrete mathematics notes?

Good morning, Do you know of a good resource for discrete mathematics notes, lectures and/or videos? I found the classes + notes given to be lacking at my university... Topics covered thus far: ...