what's the domain of y=log(x) (assuming that log is base 0)
Base 0?
\[y = \log_{0}(x)\]
should the domain be x = {0}
Ask the question: "To what power do I have to raise zero to get x?"
That doesn't find the domain.
0 ^ n = 0
Yes. \[\log_0(x):0\to\mathbb{C}\backslash\{0\}\]
You can raise 0 to the anything, but not 0, or negative.
why can't you raise 0 to 0?
Sh*ite: \(\mathbb{C^+}\)
@LolWolf what does log0(x):0→C∖{0}mean?
\[0^0 \rightarrow \text{doesn't exist}, 0^{-n} \rightarrow \text{ divide by 0}\]
It means that, \(\log_0(x)\) will 'map' (has a domain of... roughly speaking) 0 to all of the positive complex numbers, excluding zero.
Are we doing complex exponents here?
nop
Well, the reals are part of the complex, so you can just say the same thing, in this case at least, for the reals (without including the complex numbers)
Then any real number other than 0 or negatives.
@LolWolf , why DOES maths break at 0^0?
math is so complicated :S
Because we can show \(n^0\) to mean \[ \frac{n}{n} \text{ so, it'd be } \frac{0}{0}\text{which is undefined.} \]
oh i see
Because if it does, surely because of:\[a^n=1a^n=a^0a^n=a^{n+0}\], so if a=0, that means that you can't raise 0 to the anythingth power
I know I'm wrong, but which of my equalities is the fallacious one?
@henpen : \[ 0^0=1 \]
Oh, yes- I was writing as you were explaining the previous definition
so to conclude, if i were to give the domain of \[y = \log_{a}(x)\] it would be a > 0, and x = all real numbers
sorry, x > 0
It'd be: \[ a>0, a\neq1\\ x\in\mathbb{R}^+ \]
Yeah, @artofspeed , better, but make sure \(a \neq 1\)
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