Simple math question, what does log mean?
Asked by
Timebomb (
240
)
December 20th, 2009
I’ve never really taken anything above GCSE level maths, I came across this question “x5 + y / log10 = 7” and I don’t know what log means could someone explain it to me?
Observing members:
0
Composing members:
0
16 Answers
I’ve found logs to me too confusing for me to truly comprehend. Luckily no one will ask you to calculate the log of something in your head, so just learn how to deal with them via your calculator and only remember the bits that will actually be pertinent to your life. (The facts that I have learned are actually important for me to know on a regular basis: Taking the log of a number makes it smaller. If you have a data set with high outliers, using log(x) instead of your “real” numbers will give your data a more normal distribution. I know what a logarithmic graph looks like. And that’s all I’ve ever really needed to know!)
logarithm is the operation to extract the exponent from a number.
For example if you have 5^3=125 than log5(125)=5(if after log there isn’t any number it means you’re calculating logarithm for 10)
You should think logarithm like this:5 at which power equals 125.
So on your equation log 10 is(10 at which power is 10?)is simply 1
You can also read this for more explications
@Christian95 that is all correct except i believe in that example you gave, it should be log5(125)= 3 and not equal to 5. That is probably what you meant, just a typo.
Start with something really simple. !0 squared=100. 10^2 = 100
Log 100 = 2
“The logarithm of 100 to the base 10 is 2.”
2 is the exponent to which 10 must be raised to produce 100
“10^2 = 100” is called the exponential form.
“log (base 10) of 100 = 2
is called the logarithmic form.”
The inverse of an exponent in order to find the exponential value.
I have always found that concrete examples take me a lot further mathematically than the abstract reasons.
@gailcalled Most mathematicians share that sentiment, actually.
Higher level math texts generally leave out examples because the reader is expected to go about constructing them on their own.
@gailcalled Diagonalization of large matrices was my downfall.
@hiphiphopflipflapflop: That was very unhelpful, but thanks anyway. Here is my favorite sentence:
A matrix equation with an upper triangular matrix U can be solved in an analogous way, only working backwards.
Answer this question 
This question is in the General Section. Responses must be helpful and on-topic.
Composing members:
0
