Zeroth Power of Real Number equals One

Theorem

Let $a \in \R_{>0}$ be a (strictly) positive real number.

Let $a^x$ be defined as $a$ to the power of $x$.


Then:

$a^0 = 1$


Proof

\(\ds a^0\) \(=\) \(\ds \map \exp {0 \ln a}\) Definition of Power to Real Number
\(\ds \) \(=\) \(\ds \map \exp 0\)
\(\ds \) \(=\) \(\ds 1\) Exponential of Zero

$\blacksquare$


Sources

  • 1968: Murray R. Spiegel: Mathematical Handbook of Formulas and Tables ... (previous) ... (next): $\S 7$: Laws of Exponents: $7.4$
  • 2009: Murray R. Spiegel, Seymour Lipschutz and John Liu: Mathematical Handbook of Formulas and Tables (3rd ed.) ... (previous) ... (next): $\S 13$: Laws of Exponents: $13.4.$