Home / All Definitions / Numbers & Symbols / Pre-Calculus / Rho (Ρ, ρ) Definition

Rho (Ρ, ρ) Definition

Rho (Ρ, ρ) is the 17th letter of the Greek alphabet. In the system of Greek numerals it has a value of 100. It is derived from Phoenician letter res. Its uppercase form uses the same glyph, Ρ, as the distinct Latin letter P; the two letters have different Unicode encodings.

Usage in Mathematics & Science

The characters ρ and Ρ are also conventionally used outside the Greek alphabetical context in science and mathematics:

  • In the physical sciences to represent:

    • Densities: mass density, air density or charge density (ρ).

    • Resistivity (ρ).

    • Rho meson (ρ+, ρ, ρ0).

    • General quantum states.

    • Hammett Equation, ρ is used to represent the reaction constant, this is independent of the position and nature of the substituents of the benzene ring.

  • In mathematics to represent:

    • A length coordinate in polar, cylindrical, spherical, and toroidal coordinate systems, and toroidal and poloidal coordinates of the Earth's magnetic field.

    • The correlation coefficient of a population parameter.

    • The spectral radius of a matrix A denoted as ρ(A).

    • The plastic number.

    • The prime constant.

    • The sensitivity to interest rates of a pricing function.

    • The expected return of a given policy (π) in reinforcement learning, denoted ρπ

  • In economics to represent the discount rate of future cash flows.

  • In molecular biology to represent the Rho protein responsible for termination of RNA synthesis. In such occasions, it is often represented as ϱ, to avoid confusion with the Latin letter p.

  • In molecular biology to represent the Rho family of GTPases, important for cytoskeletal dynamic regulation.

  • In ecology to represent the population damping ratio where ρ = λ1 / |λ2|.

  • In computer programming:

    • The lower-case rho ρ means reshape in the APL programming language, and by extension also queries shape.

    • The lower-case rho ρ is used for the unary rename operation in relational algebra.

  • In statistics to represent Spearman's rank correlation coefficient, commonly known as Spearman's rho.

  • In options theory to represent the rate of change of a portfolio with respect to interest rates.

Greek Alphabet

The letters of the Ancient Greek Alphabet, which are frequently utilized in math and science:

Greek Alphabet

Symbol

Letter

Symbol

Letter

Uppercase

Lowercase

Uppercase

Lowercase

Α

α

Alpha

Ν

ν

Nu

Β

β

Beta

Ξ

ξ

Xi

Γ

γ

Gamma

Ο

ο

Omicron

Δ

δ

Delta

Π

π

Pi

Ε

ε

Epsilon

Ρ

ρ

Rho

Ζ

ζ

Zeta

Σ

σ

Sigma

Η

η

Eta

Τ

τ

Tau

Θ

θ

Theta

Υ

υ

Upsilon

Ι

ι

Iota

Φ

φ

Phi

Κ

κ

Kappa

Χ

χ

Chi

Λ

λ

Lambda

Ψ

ψ

Psi

Μ

μ

Mu

Ω

ω

Omega

Related Definitions

Sources

“Rho.” Wikipedia, Wikimedia Foundation, 30 Apr. 2020, en.wikipedia.org/wiki/Rho.

App

Check out our free app for iOS & Android.

For more information about our app visit here!

Add to Home Screen

Add Math Converse as app to your home screen.

App

Check out our free desktop application for macOS, Windows & Linux.

For more information about our desktop application visit here!

Browser Extension

Check out our free browser extension for Chrome, Firefox, Edge, Safari, & Opera.

For more information about our browser extension visit here!

Welcome to Math Converse

Placeholder

Placeholder

Cite This Page

QR Code

Take a photo of the qr code to share this page or to open it quickly on your phone:

Share

Cite Page
Email
Facebook
Twitter
WhatsApp
Reddit
SMS
Skype
Line
Google Classroom
Google Bookmarks
Facebook Messenger
Evernote
Telegram
Linkedin
Pocket
Douban
WeChat
MySpace
Trello
QR Code