Real Division by One

Theorem

$\forall x \in \R: \dfrac x 1 = x$


Proof

\(\ds \frac x 1\) \(=\) \(\ds x \times \frac 1 1\) Definition of Real Division
\(\ds \) \(=\) \(\ds x \times 1\) Real Number Divided by Itself
\(\ds \) \(=\) \(\ds x\) Real Number Axiom $\R \text M4$: Inverses for Multiplication

$\blacksquare$


Sources

  • 2000: James R. Munkres: Topology (2nd ed.) ... (previous) ... (next): $1$: Set Theory and Logic: $\S 4$: The Integers and the Real Numbers: Exercise $1 \ \text{(k)}$