Complex Addition Identity is Zero
Theorem
Let $\C$ be the set of complex numbers.
The identity element of $\struct {\C, +}$ is the complex number $0 + 0 i$.
Proof
We have:
| \(\ds \paren {x + i y} + \paren {0 + 0 i}\) | \(=\) | \(\ds \paren {x + 0} + i \paren {y + 0} = x + i y\) | ||||||||||||
| \(\ds \paren {0 + 0 i} + \paren {x + i y}\) | \(=\) | \(\ds \paren {0 + x} + i \paren {0 + y} = x + i y\) |
$\blacksquare$
Sources
- 1960: Walter Ledermann: Complex Numbers ... (previous) ... (next): $\S 1.2$. The Algebraic Theory
- 1967: George McCarty: Topology: An Introduction with Application to Topological Groups ... (previous) ... (next): Chapter $\text{II}$: Groups: Direct Products
- 1981: Murray R. Spiegel: Theory and Problems of Complex Variables (SI ed.) ... (previous) ... (next): $1$: Complex Numbers: Axiomatic Foundations of the Complex Number System: $7$
- 1990: H.A. Priestley: Introduction to Complex Analysis (revised ed.) ... (previous) ... (next): $1$ The complex plane: Complex numbers $\S 1.2$ The algebraic structure of the complex numbers
- 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): complex number