How Does L'Hopital's Rule Apply to Lim (1/x)^tan(x) as x Approaches 0?

  • Context: Undergrad 
  • Thread starter Thread starter felipe oteiza
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around the application of L'Hôpital's Rule to the limit of the expression \( (1/x)^{\tan(x)} \) as \( x \) approaches 0. Participants explore the behavior of the function and its limit, considering various approaches and interpretations.

Discussion Character

  • Exploratory
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • Some participants suggest applying L'Hôpital's Rule to evaluate the limit.
  • There is a discussion about the limit of \( \sin x / x \) as a related concept.
  • Multiple participants clarify the expression in question, confirming it is \( x^{-\tan x} \).
  • One participant proposes that as \( x \) approaches 0, \( \tan x \) behaves like \( x \), leading to the limit being similar to \( \lim_{x \to 0} x^x \).
  • Another participant notes that \( x^x \) can be expressed as \( e^{x \ln x} \) and evaluates the limit of \( x \ln x \) as \( x \) approaches 0, concluding it approaches 1.
  • There is a correction regarding the indeterminate form \( (1/0)^0 \) when evaluating the limit directly.

Areas of Agreement / Disagreement

Participants express differing views on the application of L'Hôpital's Rule and the interpretation of the limit, indicating that multiple competing views remain and the discussion is unresolved.

Contextual Notes

Some participants mention the indeterminate form and the need for careful evaluation, highlighting the complexity of the limit as \( x \) approaches 0.

felipe oteiza
Messages
5
Reaction score
0
l'hopital must be apply, i'll be very grateful
 
Physics news on Phys.org
Hello felipe :welcome:

Do you know the limit for ##\sin x \over x ## ?
 
oops, sorry, you mean $$x^{-\tan x}\ \ ?$$
 
BvU said:
oops, sorry, you mean $$x^{-\tan x}\ \ ?$$
yes! the last
 
Where does ##\ x^{\tan x}\ ## go for ## \ x\downarrow 0 ## ?
 
BvU said:
Where does ##\ x^{\tan x}\ ## go for ## \ x\downarrow 0 ## ?
lim ( 1/x )^tan x as x->0
 
Yes, that was my question :smile:
 
BvU said:
Yes, that was my question :smile:
I don't understand your question :frown: (my english is not very good)
 
What is the limit ##\ \ \displaystyle \lim_{x\downarrow 0}
\ x^{\tan x}\ ## ?
 
  • #10
tanx ~ x as x ->0, so problem can be looked at as [itex]\lim_{x-->0} x^x[/itex] However [itex]x^x=e^{xlnx}[/itex].
Since [itex]\lim_{x->0}xlnx=0[/itex], the final answer = 1.
 
  • Like
Likes   Reactions: felipe oteiza
  • #11
mathman said:
tanx ~ x as x ->0, so problem can be looked at as [itex]\lim_{x-->0} x^x[/itex] However [itex]x^x=e^{xlnx}[/itex].
Since [itex]\lim_{x->0}xlnx=0[/itex], the final answer = 1.
thanks
 
  • #12
Tan (0)=0 there for answer will be 1
 
  • #13
shaztp said:
Tan (0)=0 there for answer will be 1
Not by itself. The function is [itex](\frac{1}{x})^{tanx}[/itex], so as x->0, the expression becomes [itex](\frac{1}{0})^{0}[/itex] which is indeterminate.
 
  • Like
Likes   Reactions: BvU

Similar threads

  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
1
Views
1K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K