What are the values of $a$ and $b$ in this limit?

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Discussion Overview

The discussion revolves around finding the values of $a$ and $b$ in the limit expression $$\lim_{{x}\to{0 }}\frac{\sqrt{ax+b}-2 }{x}=1$$. Participants explore the conditions under which the limit exists and the implications for the parameters involved.

Discussion Character

  • Mathematical reasoning, Homework-related, Technical explanation

Main Points Raised

  • One participant suggests that for the limit to exist, the expression must be of the form 0/0, leading to the conclusion that $b = 4$.
  • Another participant applies L'Hopital's rule and calculates the derivative, arriving at the equation $\frac{a}{2\sqrt{4}}=1$, which simplifies to $a=4$.
  • A later reply questions whether $a$ can take on other values, implying uncertainty about the uniqueness of the solution.
  • One participant responds to the question about other solutions, suggesting that there may not be any other values for $a$ that satisfy the equation.

Areas of Agreement / Disagreement

Participants generally agree on the values of $b$ and $a$ being 4, but there is some uncertainty regarding whether $a$ can take on other values, indicating a lack of consensus on this point.

Contextual Notes

The discussion does not fully resolve the implications of the limit's form or the uniqueness of the values for $a$ and $b$, leaving some assumptions and conditions unexamined.

karush
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$$\lim_{{x}\to{0 }}\frac{\sqrt{ax+b}-2 }{x}=1$$
Find $a$ and $b$

Clueless!
 
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For the limit to exist, that expression must be of the form 0/0, so b = 4. Now use L'Hopital's rule to finish up.
 
so at dx $0/0$ the denominator goes to $1$ then

dx of $\sqrt{ax+4}-2$ is $\frac{a}{2\sqrt{ax+4}}$

$x\to0$ $\frac{a}{2\sqrt{4}}=1$ $a=4$

actually can't $a$ be anything
 
Last edited:
Are there any other solutions to the equation $$\frac{a}{2\sqrt4}=1$$?
 
no quess not.
 

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