Mathematics
9 Online
OpenStudy (anonymous):
solve the equation for x
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OpenStudy (anonymous):
\[\log _{4}\frac{ 1 }{ 16}=x\]
OpenStudy (uri):
convert it into index form first.
OpenStudy (anonymous):
i got this far \[16^{-1}=4^{x}\]
OpenStudy (uri):
ok 16^(-1) = 1/16
OpenStudy (uri):
4^(x) = 1/16
take log both sides
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OpenStudy (anonymous):
ahh
OpenStudy (uri):
xln(4) = ln(1/16)
OpenStudy (uri):
you able to proceed?
OpenStudy (anonymous):
\[(16)^{-1}=(4^2)^{-1}=4^{-2}\]
OpenStudy (anonymous):
so \[\frac{ \ln1/16 }{ \ln4 }\] ?
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OpenStudy (anonymous):
now, equate the exponents on both sides
OpenStudy (anonymous):
thx
OpenStudy (uri):
wait @electrokid: why convolute the problem? just (16)^(-1) then use a calculator.
OpenStudy (anonymous):
the idea is to convert the "logarithm" form to "exponent" form
OpenStudy (anonymous):
i need an exact solution also
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OpenStudy (anonymous):
you had
\[(16)^{-1}=4^x\\
(4^2)^{-1}=4^x\]
you see?
@uri were you being sarcastic?
OpenStudy (anonymous):
electrokid give uri a medal also im gonna give u one...
OpenStudy (anonymous):
but, you see, @uri?
OpenStudy (anonymous):
this problem does not need a calculator!
OpenStudy (uri):
yeah lol!
my bad :(
just havent touched logarithms for a while.
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OpenStudy (anonymous):
so x = -2?
OpenStudy (anonymous):
yep
OpenStudy (anonymous):
YAAAY!!!
OpenStudy (anonymous):
:)