Compute lim as n tends to infinity of f(xn)

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Homework Help Overview

The discussion revolves around computing the limit of a function as n approaches infinity, specifically focusing on the function f defined piecewise based on the value of its argument. The sequence in question is defined as Xn = -1/n.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants explore whether to compute the limit of f(xn) directly or to evaluate f at the limit of xn. There is an attempt to clarify the sequence values and their implications for the limit.

Discussion Status

The discussion is active with participants questioning the nature of the limit and the behavior of the function at specific points. Some guidance is provided regarding the sequence and its evaluation, but no consensus has been reached on the limit itself.

Contextual Notes

Participants are considering the implications of the piecewise definition of the function and how the sequence approaches zero as n increases. There is an emphasis on understanding the relationship between the sequence values and the function's output.

Anne5632
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Homework Statement
Compute the lim of f(xn)
Relevant Equations
Let f(X) =X if X>=0
And f(X)= x-1 if X<0
Let Xn = -1/n
As n tends to inf, the fraction goes to zero so would the lim just be X?
 
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Anne5632 said:
Homework Statement:: Compute the lim of f(xn)
Relevant Equations:: Let f(X) =X if X>=0
And f(X)= x-1 if X<0
Let Xn = -1/n

As n tends to inf, the fraction goes to zero so would the lim just be X?
Do you want to calculate:$$\lim_{n \rightarrow \infty}f(x_n)$$or$$f(\lim_{n \rightarrow \infty}x_n)$$
 
PeroK said:
Do you want to calculate:$$\lim_{n \rightarrow \infty}f(x_n)$$or$$f(\lim_{n \rightarrow \infty}x_n)$$
First one
 
Anne5632 said:
First one
Can you write out the sequence ##f(x_n)##?
 
-1, -1/2,-1/3,-1/4...
 
Anne5632 said:
-1, -1/2,-1/3,-1/4...
That's ##x_n## isn't it?
 
What's ##f(x_1)## for example?
 
PeroK said:
What's ##f(x_1)## for example?
-1?
 
Anne5632 said:
-1?
It's ##-2##, isn't it?
 
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  • #10
Anne5632 said:
As n tends to inf, the fraction goes to zero so would the lim just be X?
If you start with ##n>0##, what would the comparison relation between ##-(1/n)## and ##0## be?
 

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