Two Proofs of a0 = 1
- A
quotient of two equal exponential variables an equals one
because all factors cancel. A quotient of all variables an and
am, where m < n will have all factors cancel leaving the
exponent n-m, if an is the numerator and am is the
denominator. Therefore if m = n all factors will cancel leaving an
exponential with n-n = 0 factors or a0. But as previously
stated a quotient of two equal exponentials equals 1. Therefore a0
= 1. Q. E. D.
- Exponentials
of the same base are unique in that an
has one and only one value for each value of the exponent. Therefore a0
has one and only one value. Assume that a0 does not equal 1.
Then there will be some real number y = ax that will have two
exponential representations in the same base. But this contradicts the
uniqueness of exponential numbers in the same base. So a0 must
be equal to 1.