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knowLittle
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Homework Statement
I found that the domain of f was defined for all reals x<-1/3 and x>1/3. Now, I need to find the limits and vertical asymptotes of
##\lim _{\chi \rightarrow \dfrac {1} {3}}\dfrac {x+2} {\sqrt {9x^{2}-1}}##
According to Wolfram Alpha, there is no limit. But, I found that the limit approaches 54(80/9)^(1/2).
The Attempt at a Solution
##\dfrac {\dfrac {x} {x}+\dfrac {2} {x}} {\dfrac {\sqrt {9x^{2}-1}} {\sqrt {x^{2}}}}=\dfrac {1+\dfrac {2} {x}} {\sqrt {9-\dfrac {1} {x^{2}}}}##
Then, I use L' Hospital:
##\dfrac {-2x^{-2}} {\dfrac {1} {2}\left( 9-x^{2}\right) ^{-1 / 2}\left( -2x\right) }=\dfrac {2} {x^{3}}\sqrt {9-x^{2}}##
So, the limit approaches 54 *(80/9)^1/2
Please, help.
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