Sum of Complex Indices of Real Number
Jump to navigation
Jump to search
Theorem
Let $r \in \R_{> 0}$ be a (strictly) positive real number.
Let $\psi, \tau \in \C$ be complex numbers.
Let $r^\lambda$ be defined as the the principal branch of a positive real number raised to a complex number.
Then:
- $r^{\psi \mathop + \tau} = r^\psi \times r^\tau$
Proof
Then:
\(\ds r^{\psi \mathop + \tau}\) | \(=\) | \(\ds \map \exp {\paren {\psi + \tau} \ln r}\) | Definition of Principal Branch of Positive Real Number raised to Complex Number | |||||||||||
\(\ds \) | \(=\) | \(\ds \map \exp {\psi \ln r + \tau \ln r}\) | ||||||||||||
\(\ds \) | \(=\) | \(\ds \map \exp {\psi \ln r} \, \map \exp {\tau \ln r}\) | Exponential of Sum | |||||||||||
\(\ds \) | \(=\) | \(\ds r^\psi \times r^\tau\) | Definition of Principal Branch of Positive Real Number raised to Complex Number |
$\blacksquare$