Logarithms !

moderator locked up my previous thread and i was like wth?

I need help in logarithms its for math and i really need help.

log base 3 of 7

round to the nearest four decimals places. Thx in advance and plz dont lock this up. My math teacher is driving me insane. He wont tell me how to do it!

Well did you see exactly why your last thread was locked? Because Scott said "Help is asked for if needed." meaning, ask how to get the answer, not simply giving you the answer. You'll never learn if you do it that way.

-BGS

*locks*

Actually, I think he doesn't speak English. Viewing this, he's asking for help...

Let's see. A quick note, ^ means "to the power of" i.e. 1^3 is 1 to the 3rd power.

A logarithm is the same thing as exponents, basically.

a^b = c can be rewritten as log a of c = b

For example 2^3 = 8 is log base 2 of 8 = 3.

So, if we take your problem, log base 3 of 7, you see we have, using the variable bit that I used earlier, a and c, but not b. You can rewrite log base 3 of 7 as 3^c = 7.

thats where im confused at getting the answer. what happens is its log base 3 of 7. Plus i get a calculator to do this. So do i take log 7 / log 3 to get the answer?

Originally Posted by Rx.cl0ne

thats where im confused at getting the answer. what happens is its log base 3 of 7. Plus i get a calculator to do this. So do i take log 7 / log 3 to get the answer?

Yes that is exactly what you do. You take "log(7)/log(3)", this will give you your answer. Hope that helps.

I would like to note that the change of base formula can apply to anything so you can also take ln 7/ ln 3 to get your answer.

Wow, I'm learning so much.
It's exactly like square roots and cube roots. Once you figure out what's going where, it's easy.
number^power=product
log (number) of (product)=power
When do you take this?

in Alegebra II...

but yeah with Logs all you need are a few simple equations...:

If (A^M = X) then (Log base A of X = M)

(Log base A of X) = (Log base B of X)/(Log base B of A) <-- B is most commonly 10

there are some others that can help... but those are the 2 ur gonna use the most.

Thank you, ive allways wanted to learn this, but the adults allways say you´´ll learn it in math C, thank you once again