# Which symbol means parallel

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### Mathematical signs

[335]Mathematical signs, abbreviations commonly used in mathematics.

The most common are: = equal; ≡ identically equal, congruent (in number theory); > greater than; or = | = not equal; ~ similar; ≅ congruent (in geometry); + plus (addition sign); - minus (subtraction sign); · Or × times (multiplication sign); : by (division sign) or: related to (in proportions); √ root sign; ∞ infinite; ! Factorial (n! = Product of the n first numbers); () Sign of the binomial coefficients, e.g.

equal and parallel; | | absolute amount (e.g. | -a| = a); ± plus or minus; ∫ integral sign. In addition there are the brackets (); []; {}. - Even if the choice of letters in mathematical expressions is arbitrary, it is customary to choose certain letters for certain sizes. The most common of these standing terms are:

a, b, c ...Coefficients; c Constant; d Signs of differentiation, difference in arithmetic series, number of colons in a curve; ∂ signs of partial differentiation; eBasis of the natural logarithm system, eccentricity (in conic sections), unit (in number theory), finite number; fCoefficient of friction, function; GAcceleration due to gravity; HHeight; i Square root of the negative unit (sign of imaginary numbers); j imaginary third root of unity; k Class of curves, modules of elliptic integrals; l Natural logarithm sign; mCenter line, mass; n indefinite number; O Order of a curve; pGender of a curve, p-Function (s. Sigma functions), ∂z /x,Parameters of conic sections, acceleration; p, q, r Line coordinates in space; q Interest factor, rank, ∂z /y;Cross-section; r Pension, radius, ∂2z /x2, Substitution, number of return points of a curve, torsion radius; sSum, curve arc, ∂2z /xy, Power sums of the roots of an equation; tTime, median line, ∂2z /y2, Number of double tangents of a curve; u Links of rows; and many more Line coordinates in the plane; vSpeed; w Probability, number of turning points: x, y, z Unknown, variable, point coordinates; z complex variables.

α, β, γ known angles, coefficients; δ any small size, signs of variation, signs of the Aronhold process, ε ± 1, any small size, any small parameter; ζ Zeta function (s. Sigma functions), Changeable; η Changeable; ϑAngle, theta function, real fraction, χModule of elliptical integrals, line coordinate in space; λParameter; ξ Changeable; π Ratio of the circumference to the diameter, line coordinate in space; ρRadius, proportionality factor, radius of curvature, line coordinate in space; σ Sigma function; φAngles, adjoint curves, number theoretical function; ψ, χAngle; ω Period, homogenizing variable, angular velocity, rolling angle in roulette; ώ infinitely increasing number.

B. Bernoullian Numbers; C. Constant, Euler's constant (0.57721566 ...); D. Determinant, discriminant; E. complete elliptical integral II. genus, Euler's numbers; F.Focal point, area, hypergeometric series, elliptical integral I. genus; GGroup; J Cylinder function; K complete elliptical integral I. genus, circle, force, conic section; L. straight line; M.Modules; O Origin, surface; P. Point, spherical function; QWeight; R. Remainder of series, resultant; S.Substitution; TTangent, living force; UJob; VPotential, volume; X infinitesimal transformation. [335]

ΒBeta function; Γ Gamma function; Δ Delta amplitude, transformation determinant, size that converges to zero; ΠProduct, elliptical integral III. Genus; Σ Sum symbol; Ω Omega process; P. Power series.

Some letter combinations also serve as abbreviations: e.g. sin, cos, tg, cotg, sec, cosec for the goniometric and arc sin etc. for the cyclometric functions; log or lg logarithm. Further abbreviations can be found in the mathematical sign languages ​​(see literature).

Literature (for sign languages): [1] Schröder, Lectures on the Algebra of Logic, I-III, Leipzig 1890-95. - [2] Peano, Notations de logique mathématique, Turin 1894. - [3] Frege, conceptual writing, Halle 1879.

Wolfing.