Proof involving linear algebra

Click For Summary

Homework Help Overview

The discussion revolves around a problem in linear algebra involving a recurrence relation defined by the terms an = 2 and an+1 = (4a_n - 3) / a_n for n ≥ 1. The goal is to prove that 1 ≤ a_n ≤ a_(n+1) ≤ 3 for all n ≥ 1. Participants express confusion regarding the problem's setup and notation.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Some participants question the clarity and correctness of the initial problem statement, suggesting that it may contain errors. Others reflect on their previous experiences with similar problems and consider the implications of the recurrence relation presented.

Discussion Status

The discussion is ongoing, with participants seeking clarification on the problem's formulation. Some guidance has been offered regarding the steps of proof by induction, but there is no consensus on the correct interpretation of the problem yet.

Contextual Notes

There is uncertainty regarding the notation used in the problem, particularly with subscripts and the definition of the terms. Participants note that something may be missing or incorrectly stated in the original problem.

spoc21
Messages
85
Reaction score
0

Homework Statement


Hi, I'm supposed to solve the following question using proof by induction, and am very confused with it. It would be greatly appreciated if someone could help me solve this problem:

Let an = 2 and an+1[tex]\frac{4a_n -3}{a_n}[/tex] for n >=1. Show that 1[tex]\leq a_n \leq a_(n+1)\leq3[/tex] for all n [tex]\geq1[/tex]
please note that _ = subscript I am very confused with this problem, and would appreciate any help.Thanks!
 
Physics news on Phys.org
What you posted doesn't make sense. Check to make sure that it's written correctly.
 
spoc21 said:

Homework Statement


Hi, I'm supposed to solve the following question using proof by induction, and am very confused with it. It would be greatly appreciated if someone could help me solve this problem:

Let an = 2 and an+1[tex]\frac{4a_n -3}{a_n}[/tex] for n >=1. Show that 1[tex]\leq a_n \leq a_(n+1)\leq3[/tex] for all n [tex]\geq1[/tex]
please note that _ = subscript


I am very confused with this problem, and would appreciate any help.


Thanks!

I have myself solved something simular not so long a ago I think it suppose to say

Let [tex]a_n = 2[/tex]

Let [tex]a_{n+1} = \frac{4 {a_n}-3}{a_n}[/tex] for [tex]n \geq 1[/tex]

and then

"Show that 1[tex]\leq {a_n} \leq {a_{n+1}}\leq 3[/tex] for all [tex]n \geq 1[/tex]"

I could be wrong but this setup makes me think about a socalled recurrence relation..
But you are right it looks like something is missing.
 
Last edited:
Have you tried anything yet? Induction has some very clear steps. First, show it is true for n=1. Then assume n=k is true and see what happens with k+1.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 7 ·
Replies
7
Views
1K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 24 ·
Replies
24
Views
4K
Replies
34
Views
4K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 15 ·
Replies
15
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K