Calculus Help for College Newbie: Limit to Infinity

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Hi, I am a newbie here and a newbie too at calculus since I just started my first year in college. Anyway, there are some questions that I don't quite understand and I hope that anyone can help me with this.

http://sphotos-a.ak.fbcdn.net/hphotos-ak-ash4/269471_368130629940171_945927165_n.jpg

I am sorry for the use of an image because I think that the questions are quite complex for me to write on keyboard.

Thank you in advance. :)
 
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a) write
\frac{\sqrt{4-x^2}}{x-2}=\sqrt{-1+\frac{4}{x-2}}
b) use the fact
e=\lim_{x \rightarrow \infty} \left( 1+\frac{1}{n} \right) ^n
 
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kuskus94 said:
Hi, I am a newbie here and a newbie too at calculus since I just started my first year in college. Anyway, there are some questions that I don't quite understand and I hope that anyone can help me with this.

http://sphotos-a.ak.fbcdn.net/hphotos-ak-ash4/269471_368130629940171_945927165_n.jpg

I am sorry for the use of an image because I think that the questions are quite complex for me to write on keyboard.

Thank you in advance. :)
Hello kuskus94. Welcome to PF !

\displaystyle \frac{\sqrt{x^2-4}}{x-2}=\frac{\sqrt{(x-2)(x+2)}}{x-2}
 
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lurflurf said:
a) write
\frac{\sqrt{4-x^2}}{x-2}=\sqrt{-1+\frac{4}{x-2}}
b) use the fact
e=\lim_{x \rightarrow \infty} \left( 1+\frac{1}{n} \right) ^n

Dear lurflurf,

I sill don't get how the question a) can me modified to be like that and I would like to ask you to break it down more for me.

As for question b), I apologize that my lack of reading. It is my bad to not read the calculus book deeper. :blushing:

Thank you for your reply.

SammyS said:
Hello kuskus94. Welcome to PF !

\displaystyle \frac{\sqrt{x^2-4}}{x-2}=\frac{\sqrt{(x-2)(x+2)}}{x-2}

Dear SammyS,

I thank you for welcoming me in this forum. But then I got a waring message from Mark44 (the admin to my suppose) beacuse I didn't state that I have tried doing this question. Well, it was my bad :-p.

For the question a), I still got {\sqrt{0}} over 0. I don't think I have any other idea to workaround this question. I would be really glad if you can help me more. :biggrin:

Thank you in advance.
 
kuskus94 said:
...

Dear SammyS,

I thank you for welcoming me in this forum. But then I got a waring message from Mark44 (the admin to my suppose) because I didn't state that I have tried doing this question. Well, it was my bad :-p.

For the question a), I still got {\sqrt{0}} over 0. I don't think I have any other idea to workaround this question. I would be really glad if you can help me more. :biggrin:

Thank you in advance.
You can cancel one of the factors in the numerator. What is \displaystyle \frac{\sqrt{u}}{u}\ or \displaystyle \frac{\sqrt{3}}{3}\ ?
 
SammyS said:
You can cancel one of the factors in the numerator. What is \displaystyle \frac{\sqrt{u}}{u}\ or \displaystyle \frac{\sqrt{3}}{3}\ ?

Ah, I see... Thank you very much for your help. :)
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...

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