Is the Limit as x Approaches 2 of ((1/x)-(1/2))/(x-2) Zero?

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Homework Help Overview

The discussion revolves around evaluating the limit as x approaches 2 for the expression ((1/x)-(1/2))/(x-2). The subject area pertains to calculus, specifically limits and indeterminate forms.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to simplify the limit expression but arrives at an indeterminate form of 0/0. Some participants question the validity of concluding that this limit equals zero without further justification. Others explore the manipulation of the expression to clarify the limit's behavior.

Discussion Status

Participants are actively engaging in the discussion, with some providing guidance on how to approach the limit more rigorously. There is a focus on clarifying the steps taken in the simplification process, and multiple interpretations of the limit's value are being explored.

Contextual Notes

There is an emphasis on not prematurely concluding that 0/0 equals zero, highlighting the need for careful analysis of limits. Additionally, a side question regarding the derivative of a different function is introduced, which may indicate a broader inquiry into calculus concepts.

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Homework Statement


lim
x[tex]\rightarrow[/tex]2 ((1/x)-(1/2))/(x-2)


Homework Equations





The Attempt at a Solution


Limit x-> for all of them, too tedious to keep rewriting it
=((2/2x)-(x-2x))/(x-2)
=((2-x)/(2x))/(x-2)
=((2-x)/(2x)) * (1/(x-2))
=(2-x)/(2x^2-4x)
sub 2 in = 0/0 = 0

therefore when x approaches 2, y approaches 0?

=
 
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Never say 0/0=0. Never, until you have actually shown it. You have (2-x)/((2x)*(x-2)). (2-x)/(x-2)=-(x-2)/(x-2)=(-1). Now what's the limit?
 


Dick said:
Never say 0/0=0. Never, until you have actually shown it. You have (2-x)/((2x)*(x-2)). (2-x)/(x-2)=-(x-2)/(x-2)=(-1). Now what's the limit?


How did you go from (2-x)/((2x)*(x-2)) to (2-x)/(x-2)?
 


I didn't. I just separated (2-x)/((2x)*(x-2)) into [1/(2x)] * [(2-x)/(x-2)] and made the observation that the second factor is -1.
 


Dick said:
I didn't. I just separated (2-x)/((2x)*(x-2)) into [1/(2x)] * [(2-x)/(x-2)] and made the observation that the second factor is -1.

So then it is 0?

Btw, does the derivative of x/(2x-1) = 0?
 


TayTayDatDude said:
So then it is 0?

Btw, does the derivative of x/(2x-1) = 0?

Is what 0? No, the derivative of x/(2x-1) is not zero. Unless x=0.
 

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