How do we know which function is dominant of
lnx/x^(1/2) using l'hopitals rule

Question

How do we know which function is dominant of 
lnx/x^(1/2) using l'hopitals rule

anonymous · Answer

Thanks for coming to help

mathteacher1729 · Answer

Oh man, read this, read this RIGHT NOW -- it is an awesome introduction to relative rates of growth! http://www.math.psu.edu/ug/courses/math141

mathteacher1729 · Answer

(scroll down and read the PDF titled "relative rates of growth". )

anonymous · Answer

ok

anonymous · Answer

HUH I need to use l'hopitals rule

akshay_budhkar · Answer

you know the rule right? you need to differentiate the numerator and the denominator to get the derivative if the function has an indeterminate form

mathteacher1729 · Answer

Take the first derivative of the numerator and denomiator separately, then take the limit as x goes to + and - infinity separately.

anonymous · Answer

right so you wld differentiate them as if they were two separate functions

anonymous · Answer

and then what wld u do?

akshay_budhkar · Answer

then you right them as u'/v' which is your answer if the original fraction was u/v and where u' is the derivative of u

anonymous · Answer

ok

akshay_budhkar · Answer

also if that form also turns out to be an indeterminate form then you go on to differentiate them over again following till the time it is not an indeterminate form

anonymous · Answer

ok

akshay_budhkar · Answer

i believe you know the differentiation of the functions :) So you can go about the question right? :D

anonymous · Answer

and then how do I know which one is dominant?

anonymous · Answer

like the numerator or the denomanator?

akshay_budhkar · Answer

dominant? i dont get you?

anonymous · Answer

Evaluate the limit as x-> infinity. If it is infinity the top is dominant, if it is 0, the bottom is dominant. Use l'hopitals rule to find the limit.

anonymous · Answer

Thnaks that is what i wanted!!!!!!!

anonymous · Answer

My book is so stupid

anonymous · Answer

It just gives one exxample and says which one is dominant but doesn't explain y

anonymous · Answer

I had the same problem throughout my studies, some things in maths take a good hard think about before you can get them, so dont be discouraged :)

anonymous · Answer

Thanks

anonymous · Answer

What level of math r u in?

anonymous · Answer

I'm a graduate :) you?

anonymous · Answer

oh i am an undergraduate working to get my math major