# Symbols:Greek/Rho

From ProofWiki

## Contents

## Rho

The $17$th letter of the Greek alphabet.

- Minuscules: $\rho$ and $\varrho$

- Majuscule: $\Rho$

The $\LaTeX$ code for \(\rho\) is `\rho`

.

The $\LaTeX$ code for \(\varrho\) is `\varrho`

.

The $\LaTeX$ code for \(\Rho\) is `\Rho`

.

### Density

- $\rho$

Used to denote the density of a given body:

- $\rho = \dfrac m V$

where:

### Area Density

- $\rho_A$

Used to denote the area density of a given two-dimensional body:

- $\rho_A = \dfrac m A$

where:

The $\LaTeX$ code for \(\rho_A\) is `\rho_A`

.

### Right Regular Representation

- $\rho_a$

Let $\left ({S, \circ}\right)$ be an algebraic structure.

The mapping $\rho_a: S \to S$ is defined as:

- $\forall a \in S: \rho_a \left({x}\right) = x \circ a$

This is known as the **right regular representation of $\left ({S, \circ}\right)$ with respect to $a$**.

The $\LaTeX$ code for \(\rho_a\) is `\rho_a`

.

### Radius of Curvature

The **radius of curvature** of a curve $C$ at a point $P$ is defined as the reciprocal of the absolute value of its curvature:

- $\rho = \dfrac 1 {\left\lvert{k}\right\rvert}$