Squeeze Theorem Proof

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Squeeze Theorem Proof

In this video, I prove the squeeze theorem, which is a very classical theorem that allows us to find limits of sequences.

Other examples of limits can be seen in the playlist below.

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I have always wanted to see this proof!! This theorem is fabulous and the proof is superb!!! Thank u dr.P love u

Kdd
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In Russia we call it 'two policemen theorem' (like a two policemen (a_n, b_n) and a drunk between them (s_n))

pufitus
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Un excelente video. Este teorema en particular es utilizado frecuentemente en teoría de muestras grandes (Large sample theory) en estadística. Gracias por este video, muy útil para nosotros.

MrCigarro
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*Squeeze Theorem Proof*
*Dr Peyam*
_Class notes_

Published on Jun 30, 2020
_Squeeze Theorem Proof_
_In this video, I prove the squeeze theorem, which is a very classical theorem that allows us to find limits of sequences._
_Other examples of limits can be seen in the playlist below._

Definition of a Limit:

Check out my Sequences Playlist:

The *squeeze theorem*, also known as the *pinching theorem*, the *sandwich theorem*, the *sandwich rule*, the *squeeze lemma* . In Italy, the theorem is also known as *theorem of carabinieri* .
In many languages (e.g. French, German, Italian, Hungarian and Russian), the *squeeze theorem* is also known as the *two policemen (and a drunk) theorem*, or some variation thereof. The story is that if two policemen are escorting a drunk prisoner between them, and both officers go to a cell, then (regardless of the path taken, and the fact that the prisoner may be wobbling about between the policemen) the prisoner must also end up in the cell.

[ SQUEEZE THEOREM PROOF ]
*CLAIM* if aₙ, sₙ, bₙ are sequences
such that *aₙ ⩽ sₙ ⩽ bₙ*

And Limₙ ⃯ 𐨍 aₙ = s
and Limₙ ⃯ 𐨍 bₙ = s
then Limₙ ⃯ 𐨍 sₙ = s

Let ε > 0 be given
We know:
1) There is a N₁ such that
if N > N₁
then |aₙ - s| < ε
⇒ -ε < aₙ - s < ε
⇒ *s - ε < aₙ < s + ε*
2) There is a N₂ such that
if N > N₂
then |bₙ - s| < ε
⇒ -ε < bₙ - s < ε
⇒ *s - ε < bₙ < s + ε*

Let N = MAX{N₁, N₂}, then,
if n > N
then
-ε < aₙ - s ⩽ sₙ - s ⩽bₙ < s + ε
⇒ -ε < sₙ - s < ε
⇒ *|sₙ - s| < ε* ✔️
_we're done!_

HENCE Limₙ ⃯ 𐨍 sₙ = s ◾
( _End of proof_ ◾= Q.E.D.
_Quod Erat Demonstrandum_
Which was to be demonstrated)

alexdemoura
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I have a doubt
Can { lim as n goes to infinity of (sn+tn) } equal { lim as n goes to infinity of sn} + { lim as n goes to infinity of tn} IF sn and tn diverge??

sanjeevkumardhiman
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In German it has the ugly name "Einschnürungssatz", but i like the name Sandwitch Theorem.

cerwe
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in italy this is the "carabineros" theorem :)

russellkane
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Could this theorem be true if a_n>s_n or s_n>b_n for some natural numbers n such that they form a finite set?

luisibalaz
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When I first took calculus in the late 1970s, this was called the pinching theorem in books.

historybuff
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Cool vid Dr Peyam. Doing this one for homework made me feel like I was actually getting the hang of this analysis thing haha

sebmata
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in israel, the roughly translated name of this theorem is "the sandwich theorem"

amitir
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You are amazing, keep doing what you do!!

martyalden
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I love this channel. Dr. Peyam is just incredible. I have learned so much from him and love math just like him. I feel so inspired that I wanted to make youtube videos about my journey through mathematics, which is about to go to a new level as I start high school. I would love some support!

leoyang.
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J'ai entendu ''voilà ''.

federicodesoya
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Squeeze me with your hot theorem! Lol 😂

But seriously you rock

NotoriousSRG