help me evaluate these 3 log problems?
\[\log_\frac{ 2 }{ ?3 }\frac{ 27 }{ 8 }\]
\[\log_x \frac{ 1 }{ 9 }\]
\[\log_4x=-\frac{ 1 }{ 2 }\] *calculators are not allowed*
the second question is also equal to -1/2
First question?
\[(\log_a x = y) \rightarrow (a^y = x)\] Try and use this to solve them.
Logarithms are basically asking, to what power does "a" need to be raised to in order for you to get "x," thus the conversion equation above.
I don't understand how to do that for the first question
wait I think got it
What's the answer for the second question? Just to make sure you get the concept?
\[\frac{ 2 }{ 3 }^x=\frac{ 27 }{ 8 }\]
would that be the start to number one?
I can't really see what number one is, it's a bit bugged. Try reinputing it?
\[\log_\frac{ 2 }{ 3 }\frac{ 27 }{ 8 }\]
Ah. Yes, you're right.
okay, so I get that concept just fine :) the problem is always the next part
Will this help you? \[\frac{ a }{ b }^{-1} = \frac{ b }{ a }\]
so in this case 2/1?
\[\frac{ a }{ b }^{-x} = \frac{ b^x }{ a^x }\]
-2/1
Ok. So we have \[\frac{ 2 }{ 3 }^x = \frac{ 27 }{ 8 }\] We have to find one power that both 2 and 3 can be raised to in order to get 27 and 8. \[3^3 = 27, 2^3 = 8\] Now if you want to flip it, you merely have to add a negative sign to the exponent.
so make them both ^-3?
\[\frac{ 2 }{ 3 }^3 = \frac{ 8 }{ 27 }\] So now you just need to get \[\frac{ 27 }{ 8 }\] which can be done by changing the exponent to a negative.
wait so the answer is -3?
Yes \[\frac{ 2 }{ 3 }^ {-3} = \frac{ 27 }{ }\]
the 8 is missing lol. o_O but yeah.
ah okay! So for a more simple problem such as log_8 4 I know the answer is 2/3 but I'm not sure where I got the answer is it because 2^3 is 8 so then you make the answer 2-3?
2/3*
\[8^\frac{ 1 }{ 3 } = \sqrt[3]{8} = 2\]
okay I see! So is number 2 any different?
Different from what? o_O So \[8^\frac{ 2 }{ 3 }= \sqrt[3]{8} * \sqrt[3]{8} = 2*2 = 4\]
I meant problem 2 :D
Well no it's not, other than the negative. This may help \[x^{-\frac{ 1 }{ y }} = \frac{ 1 }{ \sqrt[y]{x} }\]and \[x^\frac{ 1 }{ y } = \sqrt[y]{x}\]
So the numerator works like an exponent, but the denominator works as the "y" root of x. Does that make sense?
Problem 2 is basically \[\frac{ 1 }{ 9 } = x^{-\frac{ 1 }{ 2 }}\]
yes it does. so is it set up as: \[\sqrt[9]{x}=\frac{ 1 }{ \sqrt{x} }\]
woah woah where did \[\sqrt[9]{x} \] come from?
Now \[\sqrt[9]{x} = x^\frac{ 1 }{ 9 }\] but \[\sqrt[9]{x} \neq \frac{ 1 }{ 9 }\]
so what do I do with x in this problem?
\[\frac{ 1 }{ 9 } = \frac{ 1 }{ \sqrt{x} }\]
so is the final answer 3?
:P Check again.
That's a square root, not a square, hehe.
so it would be 81 :D
Yeah haha.
.-. I'm so tired... I can't math... but yet I need to do 50 more problems...
hehe same. good luck!
thank you, I need all that I can get. Can you explain the 3rd problem? I think the answer is 1/2...?
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