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\[\log_{9} (1/3)\]
hahah yall are to funny!
Are you allowed to use a calculator?
yess
Familiar with change of base formula?
nopeee
zepp formula will always work and good if you are trying to get and answer quick and not worry too much but don't forget that \[\log_b(x)=y\iff b^y=x\]and you should be able to switch back and forth quicklyi
\[\log_9(\frac{1}{3})=y\iff 9^y=\frac{1}{3}\] if you can solve this you are in good shape if not, you need to get familiar with exponents
you should be thinking "9 to what power gives \(\frac{1}{3}\) ?"
yes i can get myself to this point.. I just need to get familiar with exponents.. ha but really i need help with the last part you said
ok as long as you recognize that is the crux of the problem now we can think, how can i get from 9 to \(\frac{1}{3}\) only using EXPONENTS i.e not multiplying or dividing or anything like that
hint \(\sqrt{x}=x^\frac{1}{2}\)
first off it is pretty clear that the square root of 9 is 3 right? now we recall that we can write \(\sqrt{9}=3\) or \(9^{\frac{1}{2}}=3\)
And forget the fraction 9 to the power of what gives ^3
3?
that gets us the 3, now we need the reciprocal
3/1
Reciprocal of the exponent
opps 1/3
\[\large 9^\frac{1}{2}=\sqrt{9}=3\]
Reciprocal of the exponent, not the result D:
We have to do something so 3 becomes \(\frac{1}{3}\)
okay.. im getting confused here 2/1? idk
Therefore -1/2
sorry i just get confused with all these terms :/
might i make a suggestion? because it looks like you are confused as to where to focus we have \[\log_b(x)=y\iff b^y=x\] so for example \[10^2=100\iff \log_{10}(100)=2\] \[5^3=125\iff \log_5(125)=3\] \[10^{-3}=0.001\iff \log_{10}(0.001)=-3\] \[36^{\frac{1}{2}}=6\iff\log_{36}(6)=\frac{1}{2}\] \[4^{-1}=\frac{1}{4}\iff \log_4(\frac{1}{4})=-1\] and so one what you need to focus on is the exponent
therefore when you see \[\log_9(\frac{1}{3})=y\] you think \[9^y=\frac{1}{3}\] a minus sign with give you the reciprocal and the one half will give you the square root, so your answer is minus one half
I wish I can explain that well @satellite73 :P
YAY! no @zepp you can explain very well i just get confused because everything was spread all over the place.. but what i do want to learn is how you got -1/2?
:o Thanks :) And for the reciprocal thing, it's very easy Here \[4^1=4\] right?
yesss
Alright! What you have to remember that if the exponent is negative, it will flip the number(or fraction) \[4^-1=\frac{1}{4}\]
\[4^{-1}=\frac{1}{4}\] sorry
its okay, i understood ha
Great! :D ░░░░░░░░░░░░▄▄ ░░░░░░░░░░░█░░█ ░░░░░░░░░░░█░░█ ░░░░░░░░░░█░░░█ ░░░░░░░░░█░░░░█ ███████▄▄█░░░░░██████▄ ▓▓▓▓▓▓█░░░░░░░░░░░░░░█ ▓▓▓▓▓▓█░░░░░░░░░░░░░░█ ▓▓▓▓▓▓█░░░░░░░░░░░░░░█ ▓▓▓▓▓▓█░░░░░░░░░░░░░░█ ▓▓▓▓▓▓█░░░░░░░░░░░░░░█ ▓▓▓▓▓▓█████░░░░░░░░░█ ██████▀░░░░▀▀██████▀
how did you do that????
hax
but to get 1/2 in general.. was it just guess and check? or what
Haha http://fb-art.blogspot.ca/2011/08/big-cool-facebook-like-thumb-special.html there you go :P
Nope, since the square root of 9 is 3, squareroot also means ^1/2, and we want the 3 flipped, so we add a negative sign, -1/2
in a way it is a guess, but an educated guess you have 9 as the base and you see a 3 you get from 9 to 3 by taking the square root, and you can write the square root as an exponent
of course you can also get from 9 to 3 by a) subtracting 6 b) dividing by 3 c) etc etc but you want something that you can write as an exponent, like taking powers, roots, and reciprocals
so i would say "educated guess" and practice with exponents
THANK YOU BOTH! YAY! i understand it now!!!
..oh forsure! ha
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