Modulo and congruencies in class

  • Context: Undergrad 
  • Thread starter Thread starter 1+1=1
  • Start date Start date
  • Tags Tags
    Class
Click For Summary
SUMMARY

This discussion focuses on solving problems related to modulo and congruencies, specifically finding a complete residue system mod 11 consisting of odd integers and demonstrating that for every positive integer n, \(7^n \equiv 1 + 6n \mod 36\). Participants suggest using induction and the binomial theorem to approach the latter problem. The least residue problem is also addressed, emphasizing the relationship between the remainder and least residue.

PREREQUISITES
  • Understanding of modular arithmetic and congruences
  • Familiarity with complete residue systems
  • Knowledge of induction and the binomial theorem
  • Basic concepts of factorials and their properties in modular contexts
NEXT STEPS
  • Research complete residue systems in modular arithmetic
  • Learn about induction techniques in number theory
  • Study the binomial theorem and its applications in congruences
  • Explore properties of factorials in modular arithmetic
USEFUL FOR

Students studying number theory, educators teaching modular arithmetic, and anyone interested in advanced mathematical concepts related to congruences and residues.

1+1=1
Messages
93
Reaction score
0
i am learning about modulo and congruencies in class and i am seeking some help.

i need to find a complete residue system mod 11 consisting of odds only.

show that every pos int. n, 7^n congruent to 1+6n (mod36)

find the least residue of (n-)! mod n for several values of n. find a rule but no need for a proof.

here is what i know so far...

with the least residue problem, i know that a=mq+r w/ 0<=r<1 then r is the least residue, so it is like the remainder correct? anyone offer further advise to help w/ this?

to find out the conplete resideu system of mod 11 means that m divides (a-b) where a and b are congruent to each other. any other help?

the second problem i really don't know how to do but would like help! please. :cry:
 
Physics news on Phys.org
show that every pos int. n, 7^n congruent to 1+6n (mod36)

Try induction. Or maybe you could write 7^n as (1 + 6)^n and expand it with the binomial theorem...

i need to find a complete residue system mod 11 consisting of odds only.

So you need to 10 find odd integers that are congruent to 0, 1, ..., 10 modulo 11. The first one is simple, since 11 = 0 (mod 11). The numbers which are congruent to 1 mod 11, are 1 more than a multiple of 11, i.e they are of the form 1 + 11k. Should be easy from there.
 
oooo thanks muzza! i should use the weak form of induction, that should take care of it right? choose 1 and show it holds then sub in k for n and then k+1, then go from there? wooo!

then the seconnd one i just need to use that formula to get my odd numbers mod 11? muzza you are a LIFESAVER ! (no you are really)!
 

Similar threads

  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 2 ·
Replies
2
Views
5K
  • · Replies 27 ·
Replies
27
Views
3K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 26 ·
Replies
26
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 22 ·
Replies
22
Views
6K
  • · Replies 1 ·
Replies
1
Views
4K
Replies
10
Views
6K