Where can I find a complete logarithmic formulas worksheet or tutorial?

[MrAnderson]

Homework Statement

I need to find as much as a complete logarithmic formulas worksheet or tutorials

I have not been in school for atleast 2 semesters and the class I am taking right now makes use of the basic logarithmic functions, not to complicated from what the teacher has told us. I do not remeber anything about logarithms tho so i need to refresh my memory. I am looking for the basic logarithmic formulas(properties) maybe from a website link, a worksheet or a tutorial site online? I appreciate the help.

 

[quantumdude]

Here you go...

The most basic formula is the equivalence between exponental and logarithmic equations:

$y=a^x$ if and only if $log_a(y)=x$

Next we have:

$\log_b(xy)=\log_b(x)+\log_b(y)$
$\log_b\left(\frac{x}{y}\right)=\log_b(x)-\log_b(y)$

Verbally these say that the log of a product is equal to the sum of the logs of the factors, and that the log of a quotient equals the difference of the logs of the numerator and denominator.

There is also:

$\log_b\left(a^x\right)=x\log_b(a)$

This says that a power inside of a log can be brought out front as a coefficient. A special case of this is when $a=b$:

$\log_b\left(b^x\right)=x\log_b(b)=x$

The last step is justified because $\log_b(b)=1$.

Finally we have the so-called "change of base" formula:

$$\log_a(x)=\frac{\log_b(x)}{\log_b(a)}$$

 

[MrAnderson]

Thanks for the post and for the explanation. :)