write as a single logarithm...
\[\log_{3}\sqrt{x} -\log_{3}x^{6}\]
the subscript under log is 3
Hello Laurenn ^.^ \[\huge \log_bM - \log_bN = \log_b\frac{M}N\]
i get that, i just don't know where to go from there
Well, why not do it directly? :) \[\huge = \log_3\frac{\sqrt x}{x^6}\]
But remember \[\huge \sqrt x = x^{\frac12}\]
so would it be \[-1/2\log_{3}x \] ?
Write as a single log first, and then simplify like that... start with this \(\huge =\log_3\frac{\sqrt x}{x^6}\)
how would you simplify that though?
hmm... I guess, you could do this...\[\huge =\log_3\frac{x^{\frac12}}{x^6}\] and use laws of exponents to express both with just one exponent :)
x^3?
no... \[\huge =\log_3 x^{\frac12-6}\]
so -5 and a half?
Yup :) \[\huge = \log_3x^{-\frac{11}2}\]now simplify the way you did :)
yes i got it! -11/2log3x thank you :)
can you help me with other logarithmic equations?
Sure :)
\[2\log_{5}(x-9)+\log_{5}5=3 \]
ohh... solving :) Here's another property of logs :) \[\huge \log_bM + \log_b N = \log_bMN\]
But first... \[\huge 2\log_5(x-9)=\log_b(x-9)^2\]
and then what?
Well, use the property I posted (the log M + log N = log MN)
So... \[\Large \log_5(x-9)^2 + \log_5 5 = 3\]
Or, actually, you can just remember that \[\huge \log_bb = 1\]
so log5(x-9)^2+1=3 ?
Yup :) Now bring everything with no log to the right side ^.^
so 2=log5(x-9)^2 ... would i expand x-9^2 or just leave it like that?
Nah, leave it like that :D \[\huge \log_bM = x \rightarrow b^x = M\]
So... \[\huge \log_5(x-9)^2 = 2\]\[\huge (x-9)^2=5^2\] Don't bother simplifying, just take the square root of both sides ^_^
wait so x-9=square root of 5?
@PeterPan
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