Hiya. I think this question usually doesn’t get answered with a fully true answer. Hopefully this explanation makes some sense.
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When you raise a number X to a power Y, it means you multiply the number X by itself Y times, right? Like 5^3 means 5×5×5, we multiply 5 by itself 3 times.
So what is 5^0? Can we multiply 5 by itself zero times? That’s a nonsense statement, it doesn’t really mean anything.
So maybe we can clarify a bit: when Y is a natural number (1,2,3,4,…), raising X to the power of Y means we multiply X by itself Y times.
Now, we still want to get some kind of answer when we try 5^0, or even 5^-2, even though multiplying 5 by itself 0 or -2 times is nonsense. So, we see if there’s a pattern, and then we adjust the definition of raising to a power to fit that pattern.
The pattern we might notice is this:
If we go from 5^3 = 5×5×5 to 5^2 = 5×5, we divided by 5. If we go from 5^2 = 5×5 to 5^1 = 5, we again divided by 5.
So what happens if we continue the sequence down by just following this pattern and dividing by 5 over and over?
5^3 = 5×5×5 = 125
5^2 = 5×5 = 25 ( = 5^3 ÷ 5)
5^1 = 5 = 5 ( = 5^2 ÷ 5)
5^0 = ?? = 1 ( = 5^1 ÷ 5)
5^-1 = ?? = 0.2 ( = 5^0 ÷ 5)
5^-2 = ?? = 0.04 ( = 5^-1 ÷ 5)
While the original definition “you multiply 5 by itself that many times” stops making sense, the pattern of “you divide by 5 to get to the next one” can just keep giving us the next numbers in the sequence.
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At the end of the day, the answer to “why does 5^0 = 1” is “while it’s impossible to multiply 5 by itself zero times, if we just say it’s true that 5^0 = 1, it fits nicely with our pattern. So, we say it’s true”
Anything multiplied by 0 is 0 (x * 0 = 0) – but why is that so? Because multiplying means addition multiple times, for example x*4 = x + x + x + x. Or you could say x*4 is first adding x three times, then adding x one more time: x*4 = x*3 + x*1. So far pretty obvious, so what if I wanted to say the same about 0? “Y*ou could say x*4 is first adding four times, then adding zero more times*”: x*4 = x*4 + x*0. For this last equivalence to be true, x*0 must be 0.
Now let’s rewrite exactly the same as above, but for power instead of multiplication:
Anything raised to the 0-th power is 1 (x^0 = 1) – but why is that so? Because power means multiplying multiple times, for example x^4 = x * x * x * x. Or you could say x^4 is multiplying by x three times, then multiplying by x one more time: x^4 = x^3 * x^1. So far pretty obvious, so what if I wanted to say the same about 0? “Y*ou could say x^4 is first multiplying four times, then multiplying zero more times*”: x^4 = x^4 * x^0. For this last equivalence to be true, x^0 must be 1.
The reasons in both cases are the same.
x^0 doesn’t obviously mean anything. It isn’t x*0. Instead, it would be x multiplied with x zero times, which is paradoxical.
But x^m / x^n = x^m-n . So if m=n, you have 1 = x^n / x^n = x^0 . And it works like that with other formulas. So we decided, ok if we say x^0 = 1 , that makes sense, so let’s go with it.
Not sure if anyone shared this yet, but you can think of powers as ways to arrange things.
You roll a 6 sided die, one time, there are six outcomes.
You roll a 6 sided die, five times, there are 6^5 outcomes.
If you don’t roll a die, there is one outcome. The non-action isn’t counted as zero, but it is the only possible outcome and is counted as one.
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