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January 12, 2006 at 11:58 pm #13151
log (3x-5)+log x=3
January 12, 2006 at 11:58 pm #388
:log (3x-5)+log x=3
January 13, 2006 at 12:55 am #13152Anonymous
A logarithm is a way of representing a number by the power of a base.
i. addition of logs converts to muliplying using this rule
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to view full explanation click here
log (3x^2-5x). multiply out the brackets
Convert log back to numeric format
click image to enlarge
remember: logaM =x means exactly the same thing as saying a^x = M and log means log10 or log to the base power of 10
10^3= (3x^2-5x) multiply out the power
use -b+-Sqaure root(b^2-4ac)/2a
where a is co-efficient of x^2 (the number with the x^2) ie 3
where b is co-efficient of x (the number with the x]) ie 5
and c is the number without an x term
x=19.12 and -17.44
You should learn the 6 rules relating to logs (they come in useful). I'll post a site if I come across one
January 13, 2006 at 4:07 pm #13153
January 13, 2006 at 4:29 pm #13154Anonymous
Properties of Logarithms
Saying that logaM =x means exactly the same thing as saying a^x = M .
the log of the product A*B equals the sum of the logs of A and B
the log of the quotient A/B equals the difference of the logs of A and B.
the log of A to the base a and the power p is equal to p times the log A to the base a
the log of x to the base a is equivilant to the natural log of x divided by the natural log of a. (You would use this rule if you were trying to change the base power)
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