Conjugate Limit: $\frac{\sqrt{x}-1}{x-1}$

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Homework Help Overview

The discussion revolves around evaluating the limit of the expression $\lim_{x\to 1}\frac{\sqrt{x}-1}{x-1}$, which falls under the topic of limits in calculus.

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants discuss the approach of multiplying by the conjugate to simplify the limit. There is also mention of L'Hôpital's rule as an alternative method, with some participants questioning its necessity compared to other methods.

Discussion Status

The discussion is active, with participants sharing their attempts and reasoning. Some guidance has been offered regarding the effectiveness of different approaches, but no consensus has been reached on the best method to use.

Contextual Notes

There is a note about the need to show work in order to receive help, indicating a focus on the learning process and understanding rather than just finding the answer.

walker242
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$\lim_{x\to 1}\frac{\sqrt{x}-1}{x-1}$

Homework Statement


Calculate the limit of \lim_{x\to 1}\frac{\sqrt{x}-1}{x-1}.

Homework Equations


As above.

The Attempt at a Solution


Have tried to multiplicate with the conjugate.
 
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Have tried to multiplicate with the conjugate.

Ok, what did you get? Note that you must show your work in order to get help here.
 


\lim_{x\to 1} \frac{\sqrt{x}-1}{x-1} = \lim_{x\to 1} \frac{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1)}{\left(x-1\right)\left(\sqrt{x}+1\right)} = \lim_{x\to 1} \frac{x-1}{x\sqrt{x}+x-\sqrt{x}-1} = \lim_{x\to1}\frac{x-1}{\sqrt{x}\left(x-1\right)+x-1} = \lim_{x\to1}\frac{x-1}{(x-1)(\sqrt{x}+1)} = \frac{1}{2}

So in essence, disregard me, for I am retarded. :P
 


For a retarded person, remarkably good at limits!
 


How about LHopital's rule?
 


Why? That's like using a sledgehammer to crack a walnut. Walker242's solutions is excellent- especially because it is his solution!
 


Why?
His solution is very good.
So I have no overriding reason; but LHopital is more generic.
But I am into generic, versus tricky.
 

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