Math and Science Symbols
Look up what a math, statistics, or science symbol means, how to say it, and which field the meaning belongs to.
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Element of
Said: is an element of, or in
Set membership. "x ∈ A" states that x is an element of the set A. A slash through it (∉) means "is not an element of".
- Unicode
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U+2208 - LaTeX
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\in - HTML
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∈
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For all
Said: for all, or for every
Universal quantifier. "∀x" means the statement that follows holds for every x in the domain under discussion.
- Unicode
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U+2200 - LaTeX
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\forall - HTML
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∀
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There exists
Said: there exists, or there is
Existential quantifier. "∃x" means there is at least one x for which the statement holds. "∃!" means there exists exactly one.
- Unicode
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U+2203 - LaTeX
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\exists - HTML
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∃
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Summation
Said: sum, or the sum over
Add a sequence of terms. The index and its range sit below and above the sign, as in the sum over i from 1 to n of a_i.
This is the N-ary summation sign (U+2211), distinct from the Greek capital letter sigma Σ (U+03A3).
- Unicode
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U+2211 - LaTeX
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\sum - HTML
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∑
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Product
Said: product, or the product over
Multiply a sequence of terms together, the multiplicative analogue of the summation sign.
This is the N-ary product sign (U+220F), distinct from the Greek capital letter pi Π (U+03A0).
- Unicode
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U+220F - LaTeX
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\prod - HTML
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∏
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Nabla (del)
Said: del, or nabla
The vector differential operator. Applied to a scalar field it gives the gradient; with a dot (∇·) it gives the divergence of a vector field, and with a cross (∇×) the curl.
- Unicode
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U+2207 - LaTeX
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\nabla - HTML
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∇
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Partial derivative
Said: partial, or dee
The partial derivative sign. ∂f/∂x is the derivative of f with respect to x while the other variables are held fixed.
- Unicode
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U+2202 - LaTeX
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\partial - HTML
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∂
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Infinity
Said: infinity
A quantity without bound, or a limit taken as a variable grows without bound. It is a concept, not a number you can compute with directly.
- Unicode
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U+221E - LaTeX
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\infty - HTML
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∞
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Approximately equal to
Said: approximately equal to
The two sides are close in value but not necessarily exactly equal.
- Unicode
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U+2248 - LaTeX
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\approx - HTML
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≈
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Not equal to
Said: not equal to
The two sides have different values.
- Unicode
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U+2260 - LaTeX
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\neq - HTML
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≠
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Less than or equal to
Said: less than or equal to
The left side is smaller than or equal to the right side.
- Unicode
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U+2264 - LaTeX
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\leq - HTML
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≤
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Greater than or equal to
Said: greater than or equal to
The left side is larger than or equal to the right side.
- Unicode
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U+2265 - LaTeX
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\geq - HTML
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≥
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Proportional to
Said: proportional to
One quantity is a constant multiple of another. "y ∝ x" means y equals some fixed constant times x.
- Unicode
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U+221D - LaTeX
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\propto - HTML
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∝
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Therefore
Said: therefore
Introduces a conclusion that follows from the preceding statements.
- Unicode
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U+2234 - LaTeX
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\therefore - HTML
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∴
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Subset of
Said: is a subset of
Set inclusion. "A ⊂ B" means every element of A is also in B. Some authors use it only for a proper (strict) subset; use ⊆ when equality is allowed.
- Unicode
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U+2282 - LaTeX
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\subset - HTML
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⊂
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Subset of or equal to
Said: is a subset of or equal to
Set inclusion that explicitly allows the two sets to be equal. Every element of A is in B, and A may equal B.
- Unicode
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U+2286 - LaTeX
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\subseteq - HTML
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⊆
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Union
Said: union, or cup
The set of all elements that are in A, in B, or in both.
- Unicode
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U+222A - LaTeX
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\cup - HTML
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∪
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Intersection
Said: intersection, or cap
The set of elements that are in both A and B.
- Unicode
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U+2229 - LaTeX
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\cap - HTML
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∩
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Empty set
Said: the empty set, or null set
The set with no elements. It is a subset of every set.
- Unicode
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U+2205 - LaTeX
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\varnothing - HTML
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∅
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Integral
Said: integral, or the integral of
Integration. A definite integral (with limits on the sign) gives the signed area under a curve; an indefinite integral gives a family of antiderivatives.
- Unicode
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U+222B - LaTeX
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\int - HTML
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∫
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Implies
Said: implies
Logical implication. "P ⇒ Q" means if P is true then Q is true; it says nothing about Q when P is false.
- Unicode
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U+21D2 - LaTeX
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\Rightarrow - HTML
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⇒
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If and only if
Said: if and only if, or iff
Logical equivalence. "P ⇔ Q" means each implies the other: they are true together and false together.
- Unicode
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U+21D4 - LaTeX
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\Leftrightarrow - HTML
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⇔
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Plus or minus
Said: plus or minus
Either add or subtract the quantity. Used for the two roots of a quadratic, and for a value together with its uncertainty, as in 9.8 ± 0.1.
- Unicode
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U+00B1 - LaTeX
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\pm - HTML
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±
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Multiplication sign
Said: times, or cross
Multiplication of numbers. Between vectors it denotes the cross product, whose result is a vector perpendicular to both inputs.
- Unicode
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U+00D7 - LaTeX
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\times - HTML
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×
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Division sign
Said: divided by
Division of one quantity by another.
- Unicode
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U+00F7 - LaTeX
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\div - HTML
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÷
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Square root (radical)
Said: the square root of
The principal (non-negative) square root of the quantity under the sign. A small index on the sign gives an nth root instead.
- Unicode
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U+221A - LaTeX
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\sqrt{} - HTML
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√
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Identical to / congruent
Said: is identical to, or is congruent to
Identity or definition (true for all values), or, in number theory, congruence modulo n as in "a ≡ b (mod n)".
- Unicode
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U+2261 - LaTeX
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\equiv - HTML
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≡
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Population mean
Said: mew (rhymes with few)
The mean of an entire population, the expected value of the distribution. It is estimated from data by the sample mean x-bar.
In physics the same letter denotes friction, permeability, or the prefix micro.
- Unicode
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U+03BC - LaTeX
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\mu - HTML
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μ
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Population standard deviation
Said: sig-muh
The standard deviation of a population, the square root of the variance and a measure of spread in the same units as the data. Estimated from a sample by s.
In physics the same letter denotes the Stefan-Boltzmann constant, conductivity, or stress.
- Unicode
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U+03C3 - LaTeX
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\sigma - HTML
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σ
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Population variance
Said: sigma squared
The variance of a population, the average squared deviation from the mean. Its square root is the standard deviation. The sample estimate is s-squared.
- Unicode
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U+03C3 U+00B2 - LaTeX
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\sigma^2 - HTML
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σ²
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Population correlation coefficient
Said: roh (rhymes with go)
The true (population) Pearson correlation between two variables, ranging from -1 to 1 and estimated by the sample r. Also names Spearman rank correlation.
In physics the same letter denotes density, resistivity, or charge density.
- Unicode
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U+03C1 - LaTeX
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\rho - HTML
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ρ
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Chi-squared
Said: kai-squared (kai rhymes with sky)
The chi-squared statistic and distribution, used in goodness-of-fit tests and tests of independence for categorical data. Larger values indicate greater departure from the null.
- Unicode
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U+03C7 U+00B2 - LaTeX
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\chi^2 - HTML
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χ²
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Sample mean
Said: x-bar
The arithmetic mean of a sample, the sum of the observations divided by their count. It is the usual estimate of the population mean mu.
- Unicode
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U+0078 U+0304 - LaTeX
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\bar{x} - HTML
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x̄
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Sample proportion
Said: p-hat
The observed proportion of successes in a sample, the count of successes divided by the sample size. It estimates the population proportion p.
- Unicode
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U+0070 U+0302 - LaTeX
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\hat{p} - HTML
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p̂
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Null hypothesis
Said: H-naught, or H-zero
The default claim of no effect or no difference that a test is set up to reject. A test never proves H0; it either rejects it or fails to reject it.
- Unicode
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U+0048 U+2080 - LaTeX
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H_0 - HTML
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H₀
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Alternative hypothesis
Said: H-one
The claim of a real effect or difference, accepted only when the data give enough evidence to reject the null hypothesis. Sometimes written H_a.
- Unicode
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U+0048 U+2081 - LaTeX
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H_1 - HTML
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H₁
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Significance level
Said: AL-fuh
The significance level, the probability of a Type I error (rejecting a true null hypothesis). Fixed before the test, commonly at 0.05.
In psychometrics, Cronbach alpha instead denotes a reliability coefficient.
- Unicode
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U+03B1 - LaTeX
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\alpha - HTML
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α
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Type II error rate / regression coefficient
Said: BAY-tuh
The probability of a Type II error (failing to reject a false null); statistical power equals 1 minus beta. In regression, beta is a coefficient (slope) on a predictor.
- Unicode
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U+03B2 - LaTeX
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\beta - HTML
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β
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Rate parameter
Said: LAM-duh
The rate parameter of a Poisson distribution (mean events per interval) or of an exponential distribution (events per unit time).
The same letter is wavelength, a decay constant, or an eigenvalue in other fields.
- Unicode
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U+03BB - LaTeX
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\lambda - HTML
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λ
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Generic parameter
Said: THAY-tuh
A stand-in for the unknown quantity being estimated, for example a distribution parameter in maximum-likelihood or Bayesian inference.
In geometry and physics the same letter denotes an angle.
- Unicode
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U+03B8 - LaTeX
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\theta - HTML
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θ
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Sample correlation coefficient
Said: r
The Pearson sample correlation coefficient, measuring linear association between two variables from -1 (perfect negative) through 0 (none) to 1 (perfect positive). Its square, r-squared, is the fraction of variance explained.
- Unicode
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U+0072 - LaTeX
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r - HTML
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r
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p-value
Said: p, or p-value
The probability, assuming the null hypothesis is true, of a result at least as extreme as the one observed. A small p-value is evidence against the null; it is not the probability that the null is true.
Distinct from a population proportion p, which is estimated by p-hat.
- Unicode
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U+0070 - LaTeX
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p - HTML
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p
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Sample standard deviation
Said: s
The standard deviation computed from a sample, using n minus 1 in the denominator (Bessel correction). It estimates the population standard deviation sigma.
- Unicode
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U+0073 - LaTeX
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s - HTML
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s
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Sample variance
Said: s squared
The unbiased sample variance: the sum of squared deviations from the sample mean divided by n minus 1. It estimates the population variance.
- Unicode
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U+0073 U+00B2 - LaTeX
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s^2 - HTML
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s²
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Sample size
Said: n
The number of observations in a sample. Capital N usually denotes the size of the whole population.
- Unicode
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U+006E - LaTeX
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n - HTML
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n
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Summation / covariance matrix
Said: SIG-muh (capital)
As an operator, the summation sign in formulas. In multivariate statistics, capital sigma also denotes the covariance matrix of a random vector.
The dedicated summation glyph is ∑ (U+2211); this is the Greek capital letter.
- Unicode
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U+03A3 - LaTeX
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\Sigma - HTML
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Σ
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Expectation operator
Said: E, or expectation of
The expected-value operator. E[X] is the long-run average (mean) of the random variable X; E is linear, so E[aX + b] equals aE[X] + b.
In physics the same letter denotes energy or an electric field.
- Unicode
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U+0045 - LaTeX
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\mathbb{E} - HTML
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E
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z-score / z-statistic
Said: z (zee or zed)
The number of standard deviations an observation lies from the mean. As a test statistic it follows the standard normal distribution, used when the variance is known or the sample is large.
- Unicode
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U+007A - LaTeX
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z - HTML
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z
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Student's t-statistic
Said: t
The test statistic for a mean when the population variance is unknown and estimated from the sample. It follows Student's t-distribution, which has heavier tails than the normal for small samples.
In physics t usually denotes time.
- Unicode
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U+0074 - LaTeX
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t - HTML
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t
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F-statistic
Said: F
A ratio of two variances, used in ANOVA and to compare nested models. It follows the F-distribution with a pair of degrees-of-freedom parameters.
In physics F usually denotes force.
- Unicode
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U+0046 - LaTeX
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F - HTML
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F
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Degrees of freedom
Said: new (nyoo)
The number of independent values free to vary when computing a statistic. It indexes the t, chi-squared, and F distributions and is often written df or k.
In physics the same letter denotes frequency.
- Unicode
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U+03BD - LaTeX
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\nu - HTML
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ν
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Cohen's kappa
Said: KAP-uh
A measure of agreement between two raters on categorical items that corrects for the agreement expected by chance. 1 is perfect agreement, 0 is chance-level.
In physics the same letter denotes thermal conductivity, curvature, or the dielectric constant.
- Unicode
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U+03BA - LaTeX
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\kappa - HTML
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κ
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Cohen's d
Said: d
A standardized effect size: the difference between two group means divided by their pooled standard deviation. Roughly, 0.2 is small, 0.5 medium, 0.8 large.
In calculus a lowercase d also marks a differential, as in dx.
- Unicode
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U+0064 - LaTeX
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d - HTML
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d
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Alpha (physics and chemistry)
Said: AL-fuh
Several uses: an alpha particle (a helium-4 nucleus) and alpha decay in nuclear physics; angular acceleration in mechanics; the fine-structure constant in atomic physics; the alpha carbon in chemistry.
In statistics the same letter is the significance level.
- Unicode
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U+03B1 - LaTeX
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\alpha - HTML
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α
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Beta (physics)
Said: BAY-tuh
A beta particle (an electron or positron emitted in beta decay), and in special relativity the speed ratio v/c.
In statistics the same letter is the Type II error rate or a regression coefficient.
- Unicode
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U+03B2 - LaTeX
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\beta - HTML
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β
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Gamma (physics and chemistry)
Said: GAM-uh
A gamma ray (a high-energy photon); the Lorentz factor in special relativity; the heat-capacity ratio Cp/Cv of a gas; a surface tension in physical chemistry.
- Unicode
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U+03B3 - LaTeX
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\gamma - HTML
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γ
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Delta, lowercase (small change / partial charge)
Said: DEL-tuh
A small or infinitesimal change; in chemistry a partial charge on an atom (δ+ or δ-) in a polar bond; in math and physics the Dirac delta function or the Kronecker delta.
- Unicode
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U+03B4 - LaTeX
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\delta - HTML
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δ
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Delta, capital (change / difference)
Said: DEL-tuh (capital)
A finite change in a quantity, final minus initial, as in ΔH for enthalpy change or Δx for displacement. In algebra it is the discriminant b² minus 4ac; in physics it can denote the Laplace operator.
- Unicode
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U+0394 - LaTeX
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\Delta - HTML
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Δ
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Epsilon
Said: EP-si-lon
A small positive quantity (as in epsilon-delta limits); permittivity in electromagnetism (ε0 is the vacuum permittivity); molar absorptivity in the Beer-Lambert law; strain in mechanics.
- Unicode
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U+03B5 - LaTeX
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\varepsilon - HTML
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ε
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Eta
Said: AY-tuh
Efficiency of an engine or process (output over input); dynamic viscosity in fluid dynamics.
- Unicode
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U+03B7 - LaTeX
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\eta - HTML
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η
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Theta (angle)
Said: THAY-tuh
An angle, measured in radians or degrees; in spherical coordinates the polar angle measured from the vertical axis.
In statistics the same letter denotes a generic unknown parameter.
- Unicode
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U+03B8 - LaTeX
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\theta - HTML
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θ
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Kappa (physics)
Said: KAP-uh
Thermal conductivity; the dielectric constant of a material; the curvature of a curve in geometry.
In statistics the same letter denotes Cohen's kappa.
- Unicode
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U+03BA - LaTeX
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\kappa - HTML
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κ
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Wavelength
Said: LAM-duh
The wavelength of a wave, the distance over which its shape repeats. For light it relates to frequency by the speed of light: c equals lambda times frequency.
The same letter is also a decay constant, an eigenvalue, or a Poisson rate.
- Unicode
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U+03BB - LaTeX
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\lambda - HTML
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λ
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Decay constant
Said: LAM-duh
The decay constant of a radioactive isotope: the probability per unit time that a given nucleus decays. It is the reciprocal of the mean lifetime, and the half-life is ln 2 divided by lambda.
- Unicode
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U+03BB - LaTeX
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\lambda - HTML
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λ
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Eigenvalue
Said: LAM-duh
An eigenvalue of a matrix or linear operator A: a scalar lambda for which there is a nonzero vector v with Av equal to lambda times v.
- Unicode
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U+03BB - LaTeX
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\lambda - HTML
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λ
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Mu (physics and chemistry)
Said: mew (rhymes with few)
The coefficient of friction and magnetic permeability (μ0 is the vacuum permeability) in physics; the SI prefix micro (10^-6); in chemistry the chemical potential or a molecular dipole moment.
In statistics the same letter is the population mean.
- Unicode
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U+03BC - LaTeX
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\mu - HTML
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μ
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Nu (frequency)
Said: new (nyoo)
The frequency of a wave in hertz (cycles per second), as in the photon energy E equals h times nu; also the neutrino in particle physics, and kinematic viscosity in fluids.
In statistics the same letter denotes degrees of freedom. Take care not to confuse it with v.
- Unicode
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U+03BD - LaTeX
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\nu - HTML
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ν
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Pi (the constant)
Said: pie
The ratio of a circle circumference to its diameter, about 3.14159. An irrational, transcendental number that appears throughout geometry, trigonometry, and analysis.
Capital pi Π is the product operator; a chemistry use of lowercase pi is separate.
- Unicode
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U+03C0 - LaTeX
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\pi - HTML
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π
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Pi (chemistry)
Said: pie
Osmotic pressure of a solution; a pi bond, formed by sideways overlap of p orbitals, or the pi electrons of a conjugated system.
- Unicode
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U+03C0 - LaTeX
-
\pi - HTML
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π
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Rho (physics and chemistry)
Said: roh (rhymes with go)
Density (mass per unit volume); electrical resistivity of a material; and volume charge density in electromagnetism.
In statistics the same letter is the population correlation coefficient.
- Unicode
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U+03C1 - LaTeX
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\rho - HTML
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ρ
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Sigma (physics and chemistry)
Said: SIG-muh
The Stefan-Boltzmann constant in blackbody radiation; electrical conductivity; mechanical stress (force per area); surface charge density; a scattering cross section; and a sigma bond in chemistry.
In statistics the same letter is the standard deviation.
- Unicode
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U+03C3 - LaTeX
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\sigma - HTML
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σ
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Tau
Said: taw (or rhyming with cow)
Torque in rotational mechanics; a time constant, as the RC time constant of a circuit or a mean radioactive lifetime; shear stress; the tau lepton in particle physics.
- Unicode
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U+03C4 - LaTeX
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\tau - HTML
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τ
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Phi
Said: fie or fee
A phase or angle in a wave; the golden ratio (about 1.618); the electric potential; the work function in the photoelectric effect. Magnetic flux is usually capital Phi.
- Unicode
-
U+03C6 - LaTeX
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\varphi - HTML
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φ
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Chi (chemistry and physics)
Said: kai (rhymes with sky)
Electronegativity, the tendency of an atom to attract bonding electrons, in chemistry; magnetic or electric susceptibility in physics.
In statistics the squared form chi-squared is a test statistic.
- Unicode
-
U+03C7 - LaTeX
-
\chi - HTML
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χ
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Psi (wavefunction)
Said: sigh (or psy)
The wavefunction in quantum mechanics. Its squared magnitude gives the probability density of finding a particle at a point.
- Unicode
-
U+03C8 - LaTeX
-
\psi - HTML
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ψ
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Omega, lowercase (angular frequency)
Said: oh-MAY-guh
Angular frequency or angular velocity in radians per second, equal to 2 pi times the ordinary frequency.
- Unicode
-
U+03C9 - LaTeX
-
\omega - HTML
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ω
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Omega, capital (ohm)
Said: oh-MAY-guh (capital)
The ohm, the SI unit of electrical resistance; also a solid angle in steradians, and the number of microstates in statistical mechanics.
- Unicode
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U+03A9 - LaTeX
-
\Omega - HTML
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Ω
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Phi, capital (flux)
Said: fie or fee (capital)
Flux through a surface: magnetic flux in Faraday law of induction, or electric flux in Gauss law.
- Unicode
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U+03A6 - LaTeX
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\Phi - HTML
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Φ
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Reduced Planck constant (h-bar)
Said: h-bar
The reduced Planck constant, the Planck constant h divided by 2 pi, about 1.055 times 10^-34 joule-seconds. It is the natural quantum of angular momentum and sets the scale of quantum effects.
- Unicode
-
U+210F - LaTeX
-
\hbar - HTML
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ℏ
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Degree
Said: degree, or degrees
Degrees of angle, one 360th of a full turn; or degrees of temperature, as in °C and °F.
- Unicode
-
U+00B0 - LaTeX
-
^{\circ} - HTML
-
°
No symbols match that search. Try a name (variance), a pronunciation (kai), an HTML entity, or paste the glyph itself.
curated finite symbol table with field-aware search
How?
How this reference is built
This is a fixed reference set. Each entry is a meaning in a field, so an overloaded glyph can appear more than once. Search matches the glyph, name, aliases, pronunciation, field, Unicode, LaTeX, HTML entity, notes, and plain-English meaning.
Formula: curated finite symbol table with field-aware search
Sources
- Unicode Character Code Charts. Unicode Consortium. Retrieved .
- HTML Standard, Named character references. WHATWG. Retrieved .
- Clipboard API and Events. W3C. Retrieved .
- MDN, Clipboard.writeText. MDN Web Docs. Retrieved .
- Overleaf, List of Greek letters and math symbols. Overleaf. Retrieved .
Method last reviewed