- #1
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Homework Statement
I don't know if the following is valid, so I'll appreciate if someone could tell me if it's ok. I want to find
[tex] \lim_{x\rightarrow \infty} \frac{x}{\sqrt{a^2+x^2}} [/tex]
Homework Equations
The Attempt at a Solution
Using L'Hopital rule doesn't appear to help, because repeatedly differentiating both the top and bottom gives the same limit. So I did a substitution:
[tex]x=a \tan \theta[/tex]
And the problem now becomes [tex]\lim_{\theta \rightarrow \frac{\pi}{2}} \sin \theta [/tex] which easily evaluates to 1. Is this correct?