Limit of an unknown constant expression

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SUMMARY

The limit of the expression as x approaches infinity, specifically sqrt(x^2 + ax) - sqrt(x^2 + bx), can be simplified by factoring out x from the square roots. The resulting expression is (ax - bx) / (sqrt(x^2(1 + a/x)) + sqrt(x^2(1 + b/x))). This simplification allows for the cancellation of x terms, leading to a solvable limit. The conclusion is that the limit can be determined despite the unknown constants a and b.

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Homework Statement


find limit of x as it approaches infinite sqrt(x^2+ax)-sqrt(x^2+bx)
a and b are not given

Homework Equations





The Attempt at a Solution


Looking at this equation I first eliminated the square roots. After simplifying i ended up with ax-bx/sqrt(x^2+ax)+sqrt(x^2+bx) I think that this problem cannot be solved b/c a and b are not given. Is this right or is there another way of solving this?
 
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You can't have ax-bx because that basically turns out to be ∞-∞. So you need to pull out x from the square roots so you can cancel out the x's in the numerator.

\frac{ax - bx}{\sqrt{x^2 + ax} + \sqrt{x^2 + bx}} = \frac{ax - bx}{\sqrt{x^2(1 + \frac{ax}{x^2})} + \sqrt{x^2(1 + \frac{bx}{x^2})}} = \frac{ax - bx}{x\sqrt{1 + \frac{a}{x}} + x\sqrt{1 + \frac{b}{x}}}

See where you can go from there.
 
thank you
 

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