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abannavong
Group Title
can someone help my find the limit if x>0 sinx/ cubed root of x
 one year ago
 one year ago
abannavong Group Title
can someone help my find the limit if x>0 sinx/ cubed root of x
 one year ago
 one year ago

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hartnn Group TitleBest ResponseYou've already chosen the best response.1
multiply and divide by x , to get the function in the form of sin x/ x
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
can u draw it out so i can see what ur talking about
 one year ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
\(\huge\frac{sin x}{x}\:\frac{x}{\sqrt[3]{x}}\)
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
and then from there which method would u use
 one year ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
u know the formula : \[\lim_{x \rightarrow 0}\: sinx / x = 1\] ? use that for first fraction.
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
oh ok! omg now it makes sense thank you @hartnn
 one year ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
welcome :) what did u get the final answer as ?
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
hang on lolz
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
is it 0?
 one year ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
yup, its 0 good work :)
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
thank you!!
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
i need help again actually with number 84 now
 one year ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
ok, if f(x) = root x what will be f(x+h) ?? u know?
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
im confused on tht part
 one year ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
ok, to get f(x+h) just replace x by (x+h) in f(x) so f(x+h) will be \(\sqrt{x+h}\) ok?
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
and then what?
 one year ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
i m using h instead of delta x just for convenience here. so now u put that in {f(x+h)f(x) }/ h to get \(\frac{\sqrt{x+h}\sqrt{h}}{h}\) got this ?
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
yeah i got tht part
 one year ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
now mutiply and divide by \(\sqrt{x+h}+\sqrt{h}\) and use (a+b)(ab) = a^2  b^2 and tell me what u get in numerator ?
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
oh so ur multiplying it by its conjugate right ?
 one year ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
yup, so that i get only h in numerator and that i can cancel it with h in denominator ok?
 one year ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
i made a typo ..... it should be \(\sqrt{x} \) and not \(\sqrt{h} \) in the numerator
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
wait a minute now im confused a bit
 one year ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
because itsf(x+h)  f(x) which is \(\sqrt{x+h} \) \(\sqrt{x} \)
 one year ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
so now now mutiply and divide by \(\sqrt{x+h}+\sqrt{x}\) and use (a+b)(ab) = a^2  b^2 and tell me what u get in numerator ?
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
would it still be h in the numerator i think..
 one year ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
yup, because (x+h) x = x+hx = h this h cancels out with h in denominator and u have only 1 in numerator, right ? and what u have in denominator now?
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
do you have \[\sqrt{x+h} + \sqrt{x}\]
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
idk lolz
 one year ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
yes, u are right, be confident :) now just put h =0 because lim h> 0 and tell me what u get in denominator after putting h=0
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
\[\sqrt{x+0} +\sqrt{x}\]
 one year ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
yup, thats your denominator = \(2\sqrt{x}\) and then your final answer would be \(\huge\frac{1}{2\sqrt{x}}\)
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
hang on im confused how do u get \[\frac{ 1 }{ 2\sqrt{x} }\]
 one year ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
\(\sqrt{x+0} +\sqrt{x}=\sqrt{x} +\sqrt{x}=2\sqrt{x}\) and there was 1 in the numerator, previously, right ?
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
thanks!
 one year ago

abannavong Group TitleBest ResponseYou've already chosen the best response.0
u r a very helpful math teacher!
 one year ago
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