Definition: Ratio of Two Real Numbers

A ratio of two real numbers \(a,b\) with \(b\neq 0\) is denoted by $\frac ab$ and defined as the product of the number \(a\) and the inverse number \(b^{-1},\) formally

$$\frac ab:=a\cdot b^{-1}.$$

In other words, a ratio is the result of the division of real numbers.

Definitions: 1 2
Propositions: 3 4 5 6

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  1. Forster Otto: "Analysis 1, Differential- und Integralrechnung einer Veränderlichen", Vieweg Studium, 1983