2 Log(X) + Log 0.1 = Log 5 + Log 2

a a a a

i got X= 10 , and -10

i think all answers accepted because there is power 2 in 2 Log(X)so -10 won't be refused

is that right????

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- Jun 23rd 2012, 05:56 AM #1

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- Jun 23rd 2012, 06:01 AM #2

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- Jun 23rd 2012, 06:03 AM #3

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- Jun 23rd 2012, 06:09 AM #4

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## Re: log problem

2Log X = Log X^2 is a formula for positive x only.

In general, $\displaystyle n\, log(|x|) = log(|x|^n)$

With complex numbers, you can evaluate log(-10) (it is a complex number), but you cannot use the formula given above, as -10 is not [real and] positive.

- Jun 23rd 2012, 06:45 AM #7

- Jun 23rd 2012, 07:59 AM #8

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- Jun 23rd 2012, 08:18 AM #9
## Re: log problem

- Jun 23rd 2012, 10:12 AM #10

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