Ask your own question, for FREE!
Mathematics 18 Online
OpenStudy (anonymous):

lim x->infinity lnx/sqrt infinity

OpenStudy (anonymous):

wirte the function clearly

OpenStudy (anonymous):

use L' Hospital rule ...ok

OpenStudy (anonymous):

sqrt of what?

OpenStudy (anonymous):

\[\lim_{x \rightarrow \infty} \frac{ lnx }{ \sqrt{x} }\]

OpenStudy (anonymous):

i m sorry but i think that u r given orders by this prase "use L' Hospital rule ...ok" sorry maybe another person sorry

OpenStudy (anonymous):

its okay

OpenStudy (john_es):

Using L'Hopital rule, \[\lim_{x\rightarrow∞}\frac{1/x}{1/(2\sqrt{x})}=\lim_{x\rightarrow∞}\frac{2}{\sqrt{x}}=0\]

OpenStudy (anonymous):

or use your eyeballs log grows slower than any power of \(x\)

OpenStudy (anonymous):

when u plug in the \[\infty \ -> \sqrt{x}\] y is it 0

OpenStudy (john_es):

Yes, the radical function grows faster than a constant :)

OpenStudy (anonymous):

wat?

OpenStudy (anonymous):

im asking when u plug in infinity in sqrtx why is the answer 0

OpenStudy (anonymous):

the log grows very very slowly so \[\lim_{x\to \infty}\frac{\ln(x)}{x^p}=0\] so long as \(p>0\)

OpenStudy (john_es):

Well, it is 0, because the function Square root x, grows, while the number 2 is constant, so if you do an easy calculus in a calculator, you will see that the limit is 0. Also you can check proofs with epsilon delta formalism.

OpenStudy (anonymous):

don't get it

OpenStudy (john_es):

If x is large, then you can put in the calculator x=10000, \[2/\sqrt{10000}=0.02\] \[2/\sqrt{1000000}=0.002\] So if x increases, the function "tends" to 0.

OpenStudy (anonymous):

do u mean when u plug in infinity it gets closer to zero that's y its zero

OpenStudy (john_es):

Yes, right.

OpenStudy (anonymous):

oh ok thank u :)

OpenStudy (anonymous):

y is zero because the numerator is growing slower than the denominator. not because you plug in infinity.

OpenStudy (anonymous):

|dw:1366941566074:dw|

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!