Integers Definition and 467 Threads

Let ##f(x)= \min\limits_{m, n \in \mathbb Z} \left|x- \sqrt{m^2+2 \, n^2}\right|## be the minimum distance between a positive real ##x## and a number of the form ##\sqrt{m^2 + 2 n^2}## with ##m, n## integers. Let us consider a radius ##R## and let us consider the set ##S_R## of integer points...

Hello, I was wondering how to check how much math I know and learn math up to High school level. Currently I am trying to learn the basic maths where I think i am weak. To give a light on how much i know, recently I learned that 1+1=2 is actually true. 1 cup + 1 cup = 2 cups. 2 cup - 1cup = 1...

This is one of those dumb Facebook puzzles. The only reason I'm posting it here is because I'm beginning to question my sanity. 450 responses so far have all provided the same answer. Not a single user has posted the other correct answer. A triangle has sides that are consecutive even...

I need an idea. Thank you.

Let's assume that for integers ##m## and ##n## (and integers ##x_1## and ##y_1##) the following is satisfied: $$mx_1 + ny_1 = 1$$ Then by this theorem (for some integer ##k##), if ##k|a## and ##k|b## then ##k|mx+ny## for all integers ##x## and ##y##. So it must be, $$k | mx_1 + ny_1$$ for all...

My interest is on the highlighted part ... Now to my question, in what cases do we have ##mn<(m,n)[m,n]?## I was able to use my example say, Let ##m=24## and ##n=30## for example, then ##[m,n]=120## and ##(m,n)=6## in this case we can verify that, ##720=6⋅120## implying that, ##mn≤...

Hello guys, I am able to follow the working...but i needed some clarification. By rounding to the nearest integer...did they mean? ##z=1.2-1.4i## is rounded down to ##z=1-i##? I can see from here they came up with simultaneous equation i.e ##(1-i) + (x+iy) = \dfrac{6}{5} - \dfrac{7i}{5}## to...

Does the above quantifier represent/symbolize that all of the integers ## a, b, c, d ## cannot be ## 0 ##? Is this correct?

Given the definition of whole numbers as integers, https://www.google.com/search?q=what+is+a+whole+number&rlz=1C1VDKB_en-GB&oq=what+is+a+whole+number&aqs=chrome..69i57j0i512l9.11619j0j15&sourceid=chrome&ie=UTF-8 Is it known why atom vibrations are only at whole numbers ( ref plank’s constant)...

So, a friend of mine has attempted a solution. Unfortunately, he's having numbers spawn out of nowhere and a lot of stuff is going on there which I can't make sense of. I'm going to write down the entire attempt. $$ 0 \in X \; \text{otherwise no subgroup since neutral element isn't included}...

Find all integers n such that ##\dfrac{n^2+3}{2n+4}## is an integer as well.

Is there a name for the union of {prime numbers} and {integers that are not powers of integers}? For example, we would include 2, 3, 5, 7, 11... And also 6, 10, 12... But we exclude 2^n, 3^n, ... and 6^n , 10^n , etc. What are some interesting contexts where this set crops up?

[FONT=times new roman]Problem Statement : I copy and paste the problem as it appears in the text (Lang, Basic Mathematics, 1971). Attempt : There are several questions in both a) and b) above. I type out the question and my answer each time. a) (i) Show that addition for ##E## and ##I## is...

Observe that ## \phi(1)=\phi(2)=1 ##. This implies ## \phi(1)\mid 1 ## and ## \phi(2)\mid 2 ##. Thus ## n=1 ##. Let ## n=p_{r}^{k_{1}}\dotsb p_{s}^{k_{s}} ## be the prime factorization of ## n ##. Then ## \phi(n)=n\prod_{p\mid n} (1-\frac{1}{p}) ##. Suppose ## \phi(n)\mid n ##. Then ##...

Let ## a, b, c ## and ## d ## be integers such that ## 225a+360b+432c+480d=3 ##. Then ## 75a+120b+144c+160d=1 ##. Applying the Euclidean algorithm produces: ## gcd(75, 120)=15, gcd(120, 144)=24 ## and ## gcd(144, 160)=16 ##. Now we see that ## 15x+24y+16z=1 ##. By Euclidean algorithm, we have...

Suppose that ## n=p_{1}^{k_1}p_{2}^{k_2}\dotsb p_{r}^{k_r} ## satisfies ## \phi(n)=k ##. Then ## n=\frac{k}{\prod(p_{i}-1)}\prod p_{i} ##. Note that the integers ## d_{i}=p_{i}-1 ## can be determined by the conditions ## (1) d_{i}\mid k, (2) d_{i}+1 ## is prime, and ## (3) \frac{k}{\prod d_{i}}...

Find all triples (a, b, c) of positive integers such that ##a^3+b^3+c^3=(abc)^2##.

Let ## a, a+1 ## and ## a+2 ## be the three consecutive integers. Then \begin{align*} &5^{2}\mid a\implies a\equiv 0\pmod {25}\\ &3^{3}\mid (a+1)\implies a+1\equiv 0\pmod {27}\implies a\equiv 26\pmod {9}\\ &2^{4}\mid (a+2)\implies a+2\equiv 0\pmod {16}\implies a\equiv 14\pmod {16}.\\...

im thinking i should just integrate (binominal distribution 1-2000 * prime probability function) and divide by integral of bin. distr. 1-2000. note that I am looking for a novel proof, not just some brute force calculation. (this isn't homework, I am just curious.)

Hey! 😊 I want to write a one-line Python generator or iterator expression that returns the sequence of integers generated by repeatedly adding the ascii values of each letter in the word “Close” to itself. The first 10 integers in this sequence are: 67, 175, 286, 401, 502, 569, 677, 788, 903...

Proof: Let ## N ## be an integer. Then ## N=a_{m}10^{m}+a_{m-1}10^{m-1}+\dotsb +a_{1}10+a_{0} ## for ## 0\leq a_{k}\leq 9 ##. Note that ## 10^{k}\equiv 0\pmod {4} ## for ## k\geq 2 ##. Thus ## 4\mid N\Leftrightarrow N\equiv 0\pmod {4}\Leftrightarrow a_{1}10+a_{0}\equiv 0\pmod {4} ##...

First, consider the integer ## 176521221 ##. Observe that ## 1+7+6+5+2+1+2+2+1=27 ##. Since ## 9\mid (1+7+6+5+2+1+2+2+1) ##, it follows that ## 9\mid 176521221 ##. Note that ## 1-2+2-1+2-5+6-7+1=-3 ##. This means ## 11\nmid (1-2+2-1+2-5+6-7+1) ##. Thus ## 11\nmid 176521221 ##. Therefore, the...

Proof: Let ## a ## be any integer. Then ## a\equiv 0, 1, 2, 3, 4, 5, 6, 7, 8 ##, or ## 9\pmod {10} ##. Thus ## a^{3}\equiv 0, 1, 8, 27, 64, 125, 216, 343, 512 ##, or ## 729\pmod {10} ##. Therefore, anyone of the integers ## 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 ## can occur as the units digit of ##...

Proof: Suppose for the sake of contradiction that ## r, s\in {0, ..., n-1} ## for ## r<s ## where ## c+ra\equiv c+sa\pmod {n} ##. Then ## c+ra\equiv c+sa\pmod {n}\implies ra\equiv sa\pmod {n}\implies r\equiv s\pmod {n} ##. Thus ## n\mid (r-s)\implies n<r-s ##, which is a contradiction because...

From my research I have found that since Fermat proved his last theorem for the n=4 case, one only needs to prove his theorem for the case where n=odd prime where c^n = a^n + b^n. But I am not clear on some points relating to this. For example, what if we have the term (c^x)^p, where c is an...

Proof: Let ## n>3 ## be an integer. Applying the Division Algorithm produces: ## n=3q+r ## for ## 0\leq r< 3 ##, where there exist unique integers ## q ## and ## r ##. Suppose ## n ## is prime. Then ## n=3q+1 ## or ## n=3q+2 ##, because ## n\neq 3q ##. Now we consider two cases. Case #1...

Proof: Consider all primes ## p\leq \sqrt{1949} \leq 43 ## and ## q\leq \sqrt{1951} \leq 43 ##. Then we have ## p\nmid 1949 ## and ## q\nmid 1951 ## for all ## p\leq 43 ##. Thus, ## 1949 ## and ## 1951 ## are both primes. By definition, twin primes are two prime numbers whose difference is ## 2...

## 1234=2\cdot 617 ## ## 10140=2\cdot 2\cdot 3\cdot 5\cdot 13\cdot 13 ## ## 36000=2\cdot 2\cdot 2\cdot 2\cdot 2\cdot 3\cdot 3\cdot 5\cdot 5\cdot 5\cdot ## Are the answers above correct? Or do I need to put them in canonical form as below? ## 1234=2\cdot 617 ## ## 10140=2^{2}\cdot 3\cdot 5\cdot...

Sometimes I have seen a process to build integers and rationals via a sort of Grothendieck product, Z being classes of equivalence in N x N, and Q being classes of equivalence in Z x Z. Now, I was wondering if it makes sense to consider the integers as the extension of ##\mathbb{N}## by ##\sqrt...

The following Python 3 code is provided as the solution to this problem (https://leetcode.com/problems/subsets/solution/) that asks to find all subsets of a list of integers. For example, for the list below the output is [[], [1], [1, 2], [1, 2, 3], [1, 3], [2], [2, 3], [3]]. I am not familiar...

Hello, I've been trying to solve this problem for a while, and I found a technical solution which is too computationally intensive for large numbers, I am trying to solve the problem using Combinatorics instead. Given a set of integers 1, 2, 3, ..., 50 for example, where R=50 is the maximum...

a) Yes. One surjection from ##\mathbb{Z}## to ##\mathbb{N}## is the double cover of ##\mathbb{N}## induced by ##f:\mathbb{Z}\longmapsto\mathbb{N}## with $$f(z)=\begin{cases} -z & ,\forall z<0\\ z+1 & ,\forall 0\leq z \end{cases}$$ b) Yes. One surjection from ##\mathbb{R}## to ##\mathbb{N}## is...

The probability that two randomly chosen integers to be coprimes is known to be equal to ## \prod_{2}^{\infty}(1-\frac{1}{p^2})=6/\pi^2## I tried to conceptualize the problem in the following way but got different results. Suppose that we pick up an integer at random which could be either prime...

First, read in an input value for variable inputCount. Then, read inputCount integers from input and output each integer on a newline after the string "value - ". Ex: If the input is 2 25 55, the output is: value - 25 value - 55 Code: #include <iostream> using namespace std; int main() {...

Hey! :giggle: Consider a representation of signed integers of base $B$, in which the digits are listed in descending order of importance, with the least significant digit corresponding to a positive, and the next digits to an alternate negative and positive value. Thus, a number of this...

For fun, I have decided to implement a simple XOR encryption algorithm. The first step is to convert messages into bytes to perform XOR operation on each bit. The problem has started here. For instance, I want to encrypt this message. I hiked 24 miles. Now I need to turn this text into binary...

Say for example I have a dataset (X, Y) which I need to fit to the function y = Ax^2 + By + Cxy. How do I retrieve values of A, B, and C such that they can only be integers? As of now I'm doing grid search which is so taxing.

Hi, The original problem was : for a given number k = d + n/d, where d is a divisor of another number n, how many k <= N are prime? When I looked at this problem, for k to be prime > 2, it has to be odd. This implies d and n/d can't both be even or odd. If d = 2, then d is even and n/d has...

Personal Question: Internet says the standardized math symbol for integers is ## \mathbb {Z}##. However, my Alberta MathPower 10 (Western Edition) textbook from 1998 says the symbol is I. I'm guessing that textbook is wrong? Or are both answers correct?

I've written a program to factorise large numbers (although not that large). The following arithmetic operation goes wrong: x= int(912_321_155_211_368_155/(5)) The result is 182_464_231_042_273_632 Which is clearly not right (should end in 631). The maximum integer on the 64-bit version is...

The summary abstract (describes the method) and full paper are linked. Summary abstract https://eprint.iacr.org/2021/232.pdf

I've attempted and I can retrieve a 0 when the first input is greater than the second using BRP. I can't seem to get the output of 1 if the first input is equal to the second input. I also don't get a 2 output with the first input being less than the second. I also have no idea how to loop a...

Given : The quadratic equation ##x^2+px+q = 0## with coefficients ##p,q \in \mathbb{Z}##, that is positive or negative integers. Also the roots of the equation ##\alpha, \beta \in \mathbb{Q}##, that is they are rational numbers. To prove that ##\boxed{\alpha,\beta \in \mathbb{Z}}##, i.e. the...

Maybe my problem is misunderstand the concept of " a modulo n ". I would appreciate any help to get this concept and understand the grou´p

A proper number is expressed in \pi in a similar way as a decimal integer is expressed in base 2. For example, 4375_{\pi} = 4{\pi^3}+3{\pi^2}+7{\pi}+5. The only exception I make is that the 10 digits are included when expressing a number with \pi. To clarify, the first positive such numbers are...

Let $a,\,b,\,c,\,d,\,e,\,f$ be positive integers and $S=a+b+c+d+e+f$. Suppose that the number $S$ divides $abc+def$ and $ab+bc+ca-de-ef-df$, prove that $S$ is composite.

$a,\,b$ and $c$ are positive integers that satisfy the inequality $ab+3b+2c>a^2+b^2+c^2+3$. Evaluate $a+b+c$.

I am trying to get one step further with my search for \sum_{n=1}^{\infty}\frac{1}{n^{2s+1}} . Part of the way is to calculate some algebraic expressions containing fractions with really huge numbers (as in (\frac{1}{5^{9}}+\frac{1}{7^{9}}-\frac{1}{17^{9}}-\frac{1}{19^{9}})\div...

X^3 + y^2 - z = z^3 - x^2 + y what are all the positive integers for x,y, z that satisfy this equation?

Find the number of integers $k$ in the set ${0,\,1,\,\cdots,\,2012}$ such that the combination number $\displaystyle {2012\choose k}=\dfrac{2012!}{k!(2012-k)!}$ is a multiple of 2012.