+0  
 
0
635
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avatar+1832 

 

I answer this question by this way 

 

 Dec 26, 2014

Best Answer 

 #1
avatar+118677 
+10

Hi 315, you probably already know that I am not great at limits but i have looked at yours and i have a question.  

 

$$\displaystyle \lim_{x\rightarrow 0^+}\left(sin\left(e^{-\frac{1}{x^2}}\right)\right)\\\\\\
=\displaystyle \lim_{x\rightarrow 0^+}\left(sin\left(\frac{1}{e^{\frac{1}{x^2}}}\right)\right)\\\\\\$$

 

I agree with you that this equal 0 but I don't understand why you added the middle step of =lim x tends to 0 of sine x.  I mean i know that also tends to 0 but why have you put them together?  

Is there something that I don't know about??

 Dec 27, 2014
 #1
avatar+118677 
+10
Best Answer

Hi 315, you probably already know that I am not great at limits but i have looked at yours and i have a question.  

 

$$\displaystyle \lim_{x\rightarrow 0^+}\left(sin\left(e^{-\frac{1}{x^2}}\right)\right)\\\\\\
=\displaystyle \lim_{x\rightarrow 0^+}\left(sin\left(\frac{1}{e^{\frac{1}{x^2}}}\right)\right)\\\\\\$$

 

I agree with you that this equal 0 but I don't understand why you added the middle step of =lim x tends to 0 of sine x.  I mean i know that also tends to 0 but why have you put them together?  

Is there something that I don't know about??

Melody Dec 27, 2014
 #2
avatar+1832 
+5

I did this step because when x tends to 0 ,  $$\frac{1}{e^}\frac{1}{x^2}$$ is tends to zero , so I replaced it by x  

 Dec 27, 2014
 #3
avatar+1832 
+5

This is the model answer 

 Dec 27, 2014
 #4
avatar+118677 
+5

Okay fair enough 315.  

I don't know why the model answer would have that step either.

Once again it is true it just seems very strange to me (that it is put there)

 

I assume it is suppose to make the final answer easier to get to but it doesn't work for me.

Maybe I am missing something    

I wonder if Alan could shed any light on this.  ??  Could you Alan?   

 Dec 27, 2014

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