Symbols:R
ronto-
- $\mathrm r$
The Système Internationale d'Unités symbol for the metric scaling prefix ronto, denoting $10^{\, -27 }$, is $\mathrm { r }$.
Its $\LaTeX$ code is \mathrm {r} .
ronna-
- $\mathrm R$
The Système Internationale d'Unités symbol for the metric scaling prefix ronna, denoting $10^{\, 27 }$, is $\mathrm { R }$.
Its $\LaTeX$ code is \mathrm {R} .
Radius
- $r$
Used to denote a general radius.
This includes the usage where it is used for the length of the radius vector in a spherical coordinate system.
The $\LaTeX$ code for \(r\) is r .
Relation
- $\RR$
Used to denote a general relation.
The $\LaTeX$ code for \(\RR\) is \RR .
Set of Real Numbers
- $\R$
The set of real numbers.
The $\LaTeX$ code for \(\R\) is \R or \mathbb R or \Bbb R.
Set of Non-Zero Real Numbers
- $\R_{\ne 0}$
The set of non-zero real numbers:
- $\R_{\ne 0} = \R \setminus \set 0$
The $\LaTeX$ code for \(\R_{\ne 0}\) is \R_{\ne 0} or \mathbb R_{\ne 0} or \Bbb R_{\ne 0}.
Set of Non-Negative Real Numbers
- $\R_{\ge 0}$
The set of non-negative real numbers:
- $\R_{\ge 0} = \set {x \in \R: x \ge 0}$
The $\LaTeX$ code for \(\R_{\ge 0}\) is \R_{\ge 0} or \mathbb R_{\ge 0} or \Bbb R_{\ge 0}.
Set of Strictly Positive Real Numbers
- $\R_{> 0}$
The set of strictly positive real numbers:
- $\R_{> 0} = \set {x \in \R: x > 0}$
The $\LaTeX$ code for \(\R_{> 0}\) is \R_{> 0} or \mathbb R_{> 0} or \Bbb R_{> 0}.
Extended Real Number Line
- $\overline \R$
The extended set of real numbers:
- $\overline \R = \R \cup \set {+\infty, -\infty}$
The $\LaTeX$ code for \(\overline \R\) is \overline \R .
Real Euclidean Space
- $\R^n$
Let $\R^n$ be an $n$-dimensional real vector space.
Let the Euclidean metric $d$ be applied to $\R^n$.
Then $\struct {\R^n, d}$ is a (real) Euclidean $n$-space.
The $\LaTeX$ code for \(\R^n\) is \R^n .
The $\LaTeX$ code for \(\struct {\R^n, d}\) is \struct {\R^n, d} .
Position Vector
- $\mathbf r$
The usual symbol used to denote a position vector is $\mathbf r$.
The $\LaTeX$ code for \(\mathbf r\) is \mathbf r .
Radians
- $\mathrm {rad}$
The symbol for the radian is $\mathrm {rad}$.
Its $\LaTeX$ code is \mathrm {rad} .
Partial Correlation Coefficient
- $r_{ij \cdot k}$
The symbol used to denote the partial correlation coefficient between $X_i$ and $X_j$ while keeping $X_k$ fixed is:
- $r_{ij \cdot k}$
The $\LaTeX$ code for \(r_{ij \cdot k}\) is r_{ij \cdot k} .
Real Part
- $\map \Re z$ or $\map {\mathrm {Re} } z$
The real part of a complex number $z$.
The $\LaTeX$ code for \(\map \Re z\) is \map \Re z .
The $\LaTeX$ code for \(\map {\mathrm {Re} } z\) is \map {\mathrm {Re} } z .
Resistance
- $R$
The usual symbol used to denote resistance is $R$.
Its $\LaTeX$ code is R .
Reliability
- $\map {\mathrm R} t$
The reliability of a device $D$ is the probability $\map {\mathrm R} t$ that $D$ will not fail in the time interval $\openint 0 t$.
Its $\LaTeX$ code is \map {\mathrm R} t .
Rankine
- $\rankine$
The symbol for the degree Rankine is $\rankine$.
The $\LaTeX$ code for \(\rankine\) is \rankine .
Rydberg Constant
- $R_\infty$
The symbol for the Rydberg constant is $R_\infty$.
The $\LaTeX$ code for \(R_\infty\) is R_\infty .
Rydberg Energy
- $\mathrm {Ry}$
The symbol for the Rydberg energy is $\mathrm {Ry}$.
The $\LaTeX$ code for \(\mathrm {Ry}\) is \mathrm {Ry} .
Universal Gas Constant
- $R$
The symbol for the universal gas constant is $R$.
Its $\LaTeX$ code is R .
Radius of Electron
- $r_\E$
The symbol for the electron radius is $r_\E$.
The $\LaTeX$ code for \(r_\E\) is r_\E .