Limit help(1/rad(x) - 1/rad(x^2 + x))

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Homework Statement



lim x->0+ 1/x1/2 - 1/(x2+x)1/2

Homework Equations



inf - inf

The Attempt at a Solution



I can't get x out of the bottom of the equation.
 
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I have manipulated the equation to:

x1/2(x+1) - (x2+x)1/2 / x(x+1)
 
Which I now was able to reduce to:

x(x1/2-x) / x(x+1)

which goes to:

(x1/2-x) / (x+1)

and so my limit is 0/1 which is zero.

Anyone want to check the work I would greatly appreciate it.
 
Yeah, that limit is tending to 0. It's important that it's from the positive side because of the domain of the radicals.

I simply combined the fractions and the limit went to the indeterminate form 0/0. Then I just L'Hopital ruled it into 0/1
 
Last edited:
dlp211 said:
I have manipulated the equation to:

x1/2(x+1) - (x2+x)1/2 / x(x+1)
This is not an equation - it's an expression. An equation has two expressions that are connect by =.
 
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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