Compute Limits Homework: a & b

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Homework Statement



Compute the limits:

a) \lim_{n \rightarrow \infty} n(2\sqrt{n^2 - n + 2} - 3\sqrt{n^2 + 1} + \sqrt{n^2 + 2n}),

b) \lim_{n \rightarrow \infty} n(n + 4\sqrt{n^2 + n} - 2\sqrt{n^2 - n} - 3\sqrt{n^2 + 2n}).



The Attempt at a Solution


Well, dividing by n^2 leads to nowhere as I still get \frac{0}{0}. I didn't figure out a good way to use squeeze theorem here neither. So, I'm stuck.
 
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hi aid! :smile:

yes, divide by n2, then use an expansion for everything of the form √(1 + something) :wink:
 
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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