Solving the Limit of (ex+sinx)/sinx as x->0

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Homework Help Overview

The discussion revolves around evaluating the limit of the expression (e^x + sin(x))^(1/sin(x)) as x approaches 0. Participants are exploring the mathematical concepts related to limits and the behavior of functions near zero.

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to relate the limit to the known limit of (1+x)^(1/x) and expresses confusion about transforming e^x into a simpler form. Some participants suggest taking the natural logarithm of both sides and applying L'Hôpital's rule, while others question the specifics of this approach and seek clarification on how to apply it.

Discussion Status

Participants are actively engaging with the problem, offering various approaches such as logarithmic transformation and series expansion. There is a recognition of the need to be cautious with approximations for small x, indicating a productive exploration of the topic without reaching a consensus on a single method.

Contextual Notes

There is a mention of the need to expand functions for small x and the potential pitfalls of intuitive conclusions drawn from similar limit forms. Participants are navigating the complexities of the limit evaluation process while adhering to homework guidelines.

Dell
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how do i solve this limit

Lim (ex+sinx)1/sinx
x->0

its almost oiler (1+x)1/x, at 1st looking at it i thought it was simple e, because ex when x->0 is 1, but i see i need to somehow turn the ex into 1,,, any ideas??
 
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I would take ln of both sides and then use L'Hopital's
 
both of which sides?? can you show/describe what you mean
 
take the ln and use L'Hopital.

If you just want to evaluate it, expand it first order in x should be good.

Be careful though, for small x,
[tex]e^x\approx 1+x[/tex]
and
[tex]\sin(x) \approx x[/tex]
so your "intuitive" conclusion (1+x)^{1/x} doesn't hold.
 
what do i do with the ln,?? take ln on what??
 
You have

[tex]y = \lim_{x \rightarrow 0} \left(e^{x} + sin(x)\right)^{\frac{1}{sin(x)}}[/tex]

If you take ln of both sides of the expression you have

[tex]ln(y) = \lim_{x \rightarrow 0} \frac{ln(e^{x} + sin(x))}{sin(x)}[/tex]

Now do L'Hopital's and go from there, remember in the end you want to solve for y.
 

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