Integers Definition and 474 Threads

  1. B

    Why are the trivial zeros negative even integers?

    \varsigma(s) = \sum^{\infty}_{n=1}n^{-s} If you substitute a trivial zero, let's say -2. Wouldn't it be \varsigma(s) = \sum^{\infty}_{n=1} = 1^2 + 2^2 + 3^2 + 4^2 + . . . How would this series be equals to zero? Thanks
  2. X

    Find all solutions in positive integers

    Find all solutions in positive integers a; b; c to the equation a!b! = a! + b! + c! I have rearranged and got (a!-1)(b!-1) = c!+1 And the only solutions I can find are a=3 b=3 c=4 but I can't be sure that they are the only ones. How would I go about finding other solutions? I have...
  3. M

    How to express as a quotient of base n integers

    Can someone guide me on how to express (.a1a2a3a4a5) base n as a quotient of base n integers. There is a bar over a3a4a5.
  4. M

    Show Rationals and Integers are not Isomorphic

    Homework Statement Show that the groups \textbf{Q} and \textbf{R} are not isomorphic (both under addition). This was already answered before https://www.physicsforums.com/showthread.php?t=294687", but using different theory (generators and cyclic groups). We haven't covered that stuff in class...
  5. M

    If a,m and n are positive integers with m<n

    well this is the question... if a,m and n are positive integers with m<n, then (a^(2^m)+1) is a divisor of (a^(2^n)-1)... I started using induction and it works for the first step... but for the second one i do not know if i can make induction on m... any hint would help.. thanks :)
  6. H

    Proving No Integers Exist: a^n + b^n

    Homework Statement Prove that they are no integers a,b,n>1 such that (a^n - b^n) | (a^n + b^n). Homework Equations The Attempt at a Solution Do I solve this by contradiction? If so, how do I start it?
  7. S

    Can You Solve This Unique Integer Puzzle?

    I saw this somewhere, it looks like fun but i can't seem to answer it integers: 1,2,3,4,5,6,7,8,9 \frac{a}{bc}+\frac{d}{ef}+\frac{g}{hi}=1 what is a,b,c,d,e,f,g,h,i ? pick from the above integers. (ONLY USE EACH OF THE ABOVE INTEGERS ONCE) :) bc means for example 35 (b=3 and c=5)...
  8. B

    Algebraic Ints: Prove a+b & ab Algebraic

    Homework Statement if a is an algebraic number satisfying a^3+a+1 = 0 and b is an algebraic number satisfying b^2+b-3 = 0 prove that both a+b and ab are algebraic Homework Equations The Attempt at a Solution a is root of equation x^3+x+1 = 0 and similarly b, so there exists a x = ab,and...
  9. P

    Division algorithm and unique Gaussian integers

    Homework Statement Theorem Let \alpha\neq0 and \beta be Gaussian integers. Then there are Gaussian integers \tau and \rho such that \beta=\tau\alpha+\rho and N\left(\rho\right)<N\left(\alpha\right) Problem Show that the Guassian integers \tau and \rho in the Theorem are unique if and only...
  10. C

    Find all ordered pair of integers for a diophantine equation

    Homework Statement find all orderde pairs of integers (x,y) such that x^2+y^2=4x+2y Homework Equations The Attempt at a Solution rearrange to--> x^2=4x+2y-y^2 because x and y can only be integers, y(2-y) must be divisible by x so y(2-y)>=x y(2-y)=x(x-4) x(x-4)>=x x-4>=1 x>=5...
  11. G

    What Defines the Multiplication Rules for Generalized Gaussian Integers?

    Homework Statement If \omega is and nth root of unity, define Z[\omega], the set of generalized Gaussian integers to be the set of all complex numbers of the form m_{0}+m_{1}\omega+m_{2}\omega^{2}+...+m_{n-1}\omega^{n-1} where n and m_{i} are integers. Prove that the products of generalized...
  12. P

    Showing the uniqueness of the group of integers

    Homework Statement Show that the infinite cyclic group Z is the unique group that is isomorphic to all its non-trivial proper subgroups Homework Equations The Attempt at a Solution Due to the fact that Z is cyclic and that every subgroup is a cyclic group, every subgroup of Z is a...
  13. L

    ARE integers ordered pairs of natural numbers:

    ok. some rant about definition and semantics. integers are isomorphic ordered pairs of natural numbers (a,b) w/ equivalence relation (a,b)=(c,d) iff a+d=b+c. reals are convergent sequences of rationals, etc. in mathematics, are integers simply isomorphic to the ordered pairs of...
  14. A

    Sum of the fourth powers of the first n positive integers

    Homework Statement Find a formula fo the sum of the fourth powers of the first n positive integers n ∑ i^4 (i=1) Justify your work using mathematical induction Homework Equations so i know the formula for the sum of the cubes of the first n positive integers k=n+1 ∑...
  15. W

    Calculate the Sum of Odd Integers from 15 to 240 | Find the Answer Now!

    1. Find the sum of the odd integers greater than 15 but less than 241. a. 14,336 b. 28,672 c. 14,448 d. 28896 2. an = a1 + (n-1)*d 3. I know that n = 8 and a1= 17 and d = 2. But I don't know how to get one of these answers: 14,336 28,672 14,448 28896
  16. M

    One point compactification of the positive integers

    How do we show the one point compactification of the positive integers is homeomorphic to the set K={0} U {1/n : n is a positive integer}? Say Y is the one point compactification of the positive integers. I know Y must contain Z+ and Y\Z+ is a single point. Also Y is a compact Hausdorff...
  17. Z

    I was wondering what Q/Z, or the rational numbers modulo the integers.

    I was wondering what Q/Z, or the rational numbers modulo the integers. I am struggling to visualize what the cosets may be. Thank you for your time.
  18. S

    Integers 0-9999999 containing 2 3's and 2 5's

    Homework Statement How many integers from 0-9,999,999 have exactly two 3's and two 5's as digits. Homework Equations I'm not really sure... The Attempt at a Solution The answer is 107520, if I'm not mistaken. I made a program to count it up for me, so I'm fairly sure that that is...
  19. B

    Are 3 2 1 Consecutive Integers?

    I was just wondering. the integers 1 2 3 are consecutive. are the integers 3 2 1 consecutive ?
  20. I

    Is Commutativity of Addition True for Integers?

    Homework Statement Prove that for any two integers a and b, a+b=b+a. You may use the face that this holds for natural numbers. Homework Equations The Attempt at a Solution a=(x,y), b=(u,v) x,y,u,v are natural numbers a+b = (x,y)+(u,v) = (u,v)+ (x,y) = b+a I'm not sure if my...
  21. F

    Combinatroics 4-permuations of positive integers

    Homework Statement How many 4-permutations of the positive integers not exceeding 100 contain three consecutive integers k, k+1, k+2, in the correct order: a) where these consecutive integers can perhaps be separated by other integers in the permutation? b) where they are in...
  22. J

    Sum of reciprocals of integers is given - find integers

    Homework Statement The sum of the reciprocals of two consecutive odd integers is 28/195. Find the two integers. Homework Equations ? The Attempt at a Solution 28/195= 1/x + 1/(x-2) Solved using quadratic formula and got 3.44, which does not seem to be right.. Any help?
  23. E

    Proving Algebraic Integers: a + b and ab from Given Equations

    Homework Statement If a is an algebraic integer with a^3 + a + 1 = 0 and b is an algebraic integer with b^2 + b - 3 = 0, prove that both a + b and ab are algebraic integers. Homework Equations An algebraic number is said to be an algebraic integer if it satisfies an equation of the form...
  24. A

    Proving If Two Integers Don't Divide by 3: A Number Theory Challenge

    Hi, i have just registered to the forum, because this time i study number theory and in some problems i can't figure out how to solve them. This time i have to prove: If two integers x,y doesn't divided with 3 then the (x^2 - y^2) always is divided with 3. Does anyone has a clue how to...
  25. A

    Random walk on integers with two absorbing boundaries

    Hi - I am trying to find the probability of hitting one of two boundaries in a simple random walk (I describe the problem precisely below). Actually, my main concern is to find the probability distribution over time to hit either one of two boundaries. I think that this is a very standard...
  26. B

    Solve 4th Order Polynomial w/Integer Coefficients: Algebraic Int

    The rest of this sheet of problems was a piece of cake, and I think this is meant to be one of the easier problems on it, but I'm not quite sure how to do it. Homework Statement Find a fourth order polynomial with integer coefficients for which 1+\sqrt{5}-2\sqrt{3}The Attempt at a Solution I...
  27. C

    Permutations and directions of Integers

    Given this permutations {1,2...,n}, prove that the directions of 1 and 2 never change. Proof: When generating permutations, one starts with everything having a left facing arrow. In order to determine what is mobile, the arrow must be pointing towards a smaller integer. 1 points to nothing...
  28. K

    Decimal integers with nonzero digits and sum of powers puzzle

    Determine all possible positive decimal integer(s) P = X1X2X3….Xn, where P>=2 with none of the digits in P being zero, that satisfy this equation: P = X1^X1 + X2^X2 + ……+ Xn^Xn (For example, P = 234 cannot be a solution since 2^2 + 3^3 + 4^4 is equal to 287, not 234.) Notes: (i)...
  29. J

    Integer Representation Through Multiplication of Integers

    Hello, Can an integer always be represented through the multiplication of two or more integers? (Are all integers divisible by some set of 2 or more integers (- or +)?) For example, 8 is can be represented by 1 x 8, 2 x 4 and 2 x 2 x 2. But what about 257 or even - integers? I'm trying...
  30. P

    Please help with finding all integers to an equation

    How can i find all integers to this equation? 3(x+y)-xy=0 I allready found just by tring that if x=y then its 6 and x=12 ,y=4 (x=4 and y=12) I think that there are more, but how can i find all of them? PS. the first task was: 1/x + 1/y = 1/3 and then i had to find all integers...
  31. F

    Is the set of integers Z={0,+-1,+-2, } .

    Is the set of integers Z={0,+-1,+-2,...}... Hi, Can anybody help me. I know that integers under Addition is a group, but Is the set of Integers Z={0,+-1,+-2,...} together with the operation of subtraction a (noncommutative) group. Thanks a lot Flor
  32. P

    Subtracting integers with powers

    Homework Statement Hey, sorry about this. Its really obvious, i think there's just some really simple way to do it. Its annoying me, my teacher couldn't do it either! Evaluate 6667²-3333² (without a calculator) Homework Equations The Attempt at a Solution I know there is just...
  33. G

    Solving Integer Questions: Showing x, y, and z are Even

    i've come across a question thatr reads x^3 + 2y^3 + 4z^3 =0 show that x y z are all even part 2 requires to show that there are no such intergers i have no idea at all how to show something is even can anyone help please thanks
  34. J

    Set of Integers: Open or Closed?

    Homework Statement is the set of integers open or closed Homework Equations The Attempt at a Solution I thought not closed open because R/Z=Union of open intervals like ...U(-1,0)U(0,1)U...
  35. E

    Ring of Integers Isomorphism Problem

    Homework Statement Let N = AB, where A and B are positive integers that are relatively prime. Prove that ZN is isomorphic to ZA x ZB. The attempt at a solution I'm considering the map f(n) = (n mod A, n mod B). I've been able to prove that it is homomorphic and injective. Is it safe to...
  36. Ö

    Solving for Integer Pairs: 1 + 2^x + 2^(2x+1) = y^2

    Determine all pairs (x, y) of integers such that 1 + 2^x + 2^(2x+1) = y^2. ^=Exponent
  37. S

    Integers. I on this one please?

    Integers. I need help on this one please? Hi, i am trying to analyze the following problem, but i am new at abstract algebra so i am not sure whether i am reasoning properly. Problem: Why are there no integers x and y with x^2-y^2=34. Here is how i am reasoning: x^2-y^2=(x-y)(x+y)=34...
  38. M

    Integers reachable by ax + by + 30xy

    I am working on a problem and encountered the following problem: Given a,b element of {1,7,11,13,17,19,23,29} and also given that : x,y element of N+{0}. Now I want to *formlulate* the numbers that are _not_ reachable by the equation : z = ax + by + 30xy The formula(tion) should tell...
  39. D

    Find all integers with b=a^n such that a^2 + b^2 is divisible by ab+1

    Let a be a positive integer. Find all positive integers n such that b = a^n satisfies the condition that a^2 + b^2 is divisible by ab + 1. Obviously if a=1 then all n work. Otherwise, we have a^2 + b^2 = a^2 (1+a^{2(n-1)}). Also, a^2 and a^{n+1} + 1 are relatively prime, so we need to find all...
  40. P

    How to search for duplicate values in an array of integers?

    I'm trying to search for duplicate values in a array of integers in Java. The array of intergers is sorted. Could anyone give me an idea on how to get started. :confused:
  41. E

    Need help with proof of sets of integers

    1.From the problem statement Let Z+ be the set of all positive integers; that is, Z+ = {1,2,3,...} Define Z+ x Z+ = {(a1, a2) : a1 is an element of Z+ and a2 is an element of Z+ } 2. If S is contained in Z+ and |S| >=3, prove that there exist distinct x,y that are elements of S such...
  42. A

    Irreducibility over Integers mod P

    Homework Statement a. Prove that x^2+1 is irreducible over the field F of integers mod 11. b. Prove that x^2+x+4 is irreducible over the field F of integers mod 11. c. Prove that F[x]/(x^2+1) and F[x]/(x^2+x+4) are isomorphic. Homework Equations A polynomial p(x) in F[x] is said to...
  43. K

    Common multiple of positive integers

    Just have this question I am having trouble with The least common multiple of positive integers a, b, c and d is equal to a + b + c + d. Prove that abcd is divisible by at least one of 3 and 5. Thanks
  44. S

    Computing Large Integers with Precision: Solving Equations with x=10^30

    Homework Statement I need to find some huge numbers and don't know how to do it using a computer. Everything that I have tried doesn't work because the numbers are too big. Homework Equations The equations are 1/((1-x)(1-x^2)(1-x^3)) and 1/((1-x)(1-x^3)(1-x^4)) where x=10^30. The...
  45. C

    Proving: 6 Divides (n^3-n) for All Integers n

    Homework Statement prove:6 divides (n^3-n) for all integers n. Homework Equations n^3-n=(n)(n+1)(n-1) The Attempt at a Solution tried to use direct proof. Then used cases that involed n=2k for some integer k and n=2k+1 for some integer k. However, i could not get it so that 6 was...
  46. C

    Proving Existence of Integer y and z for x in Positive Integers

    Homework Statement Prove that for all x there exists and x if it is an element of the positive integers, then there is an integer y and an integer z. Homework Equations The Attempt at a Solution I know that the contrapositive would be "If there is not an element of the positive...
  47. D

    Problem of distinct integers chosen from the arithmetic progression

    I have a solution to a problem which I am not certain that is complete. (It's a putnam problem so I can't believe I solved it) Would you mind to take a look at it? The problem stated: "Let A be any set of 20 distinct integers chosen from the arithmetic progression 1,4,7,...,100. Prove that...
  48. A

    What is the Solution to Finding a Set of n+1 Integers from 2n?

    [SOLVED] Set of n+1 integers from 2n [deleted by user]
  49. D

    Zero product property for integers

    Hi, I am just wondering if the zero product property (ab=0 implies a=0 or b=0) can be proven on the integers, or is it directly axiomatic to the defining of the integers? Also, where might I find a definition of the integer axioms? Thanks a lot,
  50. T

    Sum of the square root of integers from 1 to n

    Homework Statement I want to know what's the formula to calculate the sum of the square root of integers from 1 to n. I got an identity from wikipedia but its too complicated for me, it involves bernoulli's number, i don't know what is that. Homework Equations The Attempt at a...
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