What is 0 to the power of 0?

1 Answer
Jun 24, 2015

This is actually a matter of debate. Some mathematicians say 0^0 = 100=1 and others say that it is undefined.

Explanation:

See the discussion on Wikipedia:
Exponentiation : Zero to the power of zero

Personally I like 0^0=100=1 and it works most of the time.

Here's one argument in favour of 0^0 = 100=1 ...

For any number a in RR the expressions a^1, a^2, etc. are well defined:

a^1 = a
a^2 = a xx a
a^3 = a xx a xx a
etc.

For any positive integer, n, a^n is the product of n instances of a.

So what about a^0?

By analogy, that's an empty product - the product of 0 instances of a. If we define the empty product as 1 then all sorts of things work well. It makes sense as 1 is the multiplicative identity. If we were talking about the empty sum, then the value 0 would be natural.

If we're happy with that, what about 0^0?

If it's the empty product of 0 instances of 0, then it is 1 too.

Unfortunately, if we look at fractional exponents, we get some nasty behaviour.

Consider (2^-n)^(-1/n) for n = 1, 2, 3,...

As n -> oo, 2^-n -> 0 and -1/n -> 0

so you would hope (2^-n)^(-1/n) -> 0^0 as n->oo

but (2^-n)^(-1/n) = 2 for all n in { 1, 2, 3,... }

So exponentiation behaves badly in the neighbourhood of 0