The branch of mathematics which deals with the properties and relations of numbers using symbols (usually letters of the alphabet) to represent numbers or members of a specified set; the generalization and extension of arithmetic.
Algebra, from M.L., from Ar. al jabr "reunion of broken bones," the first known use in the title of a book by the Persian mathematician and astronomer Abu Ja'far Mohammad ibn Musa al-Khwarizmi (c780-c850), who worked in Baghdad under the patronage of Caliph Al-Mamun. The full title of the tratise was Hisab al-Jabr w'al-Muqabala "Arithmetic of Completion and Balancing." → algorithm.
Jabr, from Ar. al jabr, as above.
Relating to, involving, or according to the laws of algebra.
Fr.: équation algébrique
An equation in the form of P = 0, where P is a → polynomial having a finite number of terms.
Fr.: fonction algébrique
A function expressed in terms of → polynomials and/or roots of polynomials. In other words, any function y = f(x) which satisfies an equation of the form P0(x)yn + P1(x)yn - 1 + ... + Pn(x) = 0, where P0(x), P1(x), ..., Pn(x) are polynomials in x.
adad-e jabri (#)
Fr.: nombre algébrique
A number, → real or → complex, that is a → root of a → non-zero polynomial equation whose → coefficients are all → rational. For example, the root x of the polynomial x2 - 2x + 1 = 0 is an algebraic number, because the polynomial is non-zero and the coefficients are rational numbers. The imaginary number i is algebraic, because it is the solution to x2 + 1 = 0.
Algenib (γ Pegasi)
Algenib, from Ar. Aljanb al-Faras "the horse's flank," from al "the" + janb "flank" + faras "horse".
Algieba (γ Leo)
A binary system in Leo the brighter component of which (magnitude 2.6) is a giant K star and the partner a giant G (magnitude 3.8). The angular separation of just over 4'' means that the two stars are at least 170 AU apart, for a distance of 126 → light-years, and have an orbital period of over 500 years.
Algieba, from Ar. Al-Jabhah "the forehead" (of the Lion).
Algol (β Persei)
Alqul, Ra's-ol-Qul (#)
A variable star in the constellation → Perseus, which was the first eclipsing binary discovered. Its brightness varies between 2.2 and 3.5 magnitudes. Lying at a distance of about 82 → light-years, it consists of at least three components. The brightest component (A) is of spectral type B8 V, and the second one (B) a K type giant. The components A and B turn around each other with a period of about 68.8 hours.
Algol, from Ar. Ra's al-ghul "the ghoul's head".
Fr.: variables de type Algol
The same as eclipsing binary stars, the prototype of which is Algol.
A step-by-step problem-solving procedure, especially an established, recursive computational procedure for solving a problem in a finite number of steps.
From M.L. algorismus, a mangled transliteration of al-Khwarizmi, "native of Khwarazm," the surname of the Persian mathematician and astronomer Abu Ja'far Mohammad ibn Musa al-Khwarizmi (c780-c850).
General:An assumed name; otherwise called.
From L. alius "(an)other". Compare with Skt. anya "other, different," Av. anya-, O.Pers. aniya- "the one or the other," Arm. ail, Gk. allos "another," Goth. aljis "other". PIE *al- "beyond".
Anyâ from Mid.Pers. anya "other, otherwise," from Av. anya "other". This term is used as eyni in the Modern Persian Aftari dialect: eyni sâl "other year," eyni vacé "other child".
The condition that two or more functions are indistinguishable because they have the same values at a finite set of points. Such functions are said to be aliases of each others. The aliasing problem often occurs in undersampled discrete Fourier transform.
Anyâyi, from anyâ, → alias, + noun forming suffix -i.
1) In a → planispheric astrolabe,
the small revolving rod fixed to the center of
the goniometric scale plotted on the → front
or → back of the instrument.
Unlike the → rule,
the alidade has little vanes with holes or slots at each
end, called → pinnules, which are used as sights,
through which the observer can aim at a particular object. An index, often consisting of
the edge of the alidade itself, shows on the goniometric scales the
angle between the line of sight of the targeted object and a
predetermined axis, i.e. the vertical of the observation locality
(online museo galileo, VirtualMuseum).
M.E. allidatha, alhidade, from L. alhidada, from Ar.
Ezâdé, from Ar. al-'izâda.
bigâné (#), bigân
Fr.: 1) espèce envahissante; 2) extraterrestre
1) A species not native to its environment; an introduced species.
M.E., from O.Fr. alien "strange, foreign; a stranger, foreigner," from L. alienus "of or belonging to another, foreign, alien, strange," also, as a noun, "a stranger, foreigner," adjectival form of alius "(an)other," → alias; meaning "not of the Earth" first recorded 1920.
Bigâné "alien, foreigner," from Mid.Pers. bêgânag, from bêg-, bê- "out, outside, apart" (cf. Sogd. bêk "out, outside, apart, except," bêk-dênê "heretic," literally "out of religion") + suffix -ânag.
To arrange in a line or so as to be parallel; to adjust to produce a proper relationship or orientation.
M.Fr. aligner, from O.Fr. aligner, from à "to" + ligner "to line," from L. lineare, from linea "linen thread, string, line;" → line.
Âxatidan, from â- intesive and nuance prefix + xat, → line, + infinitive suffix -idan.
align a telescope
âxatidan-e durbin, ~ teleskop
Fr.: aligner un télescope
Setting the axis of a telescope parallel to prime directions. In equatorial mounting, they are made parallel with the Earth's axis of rotation and the equator respectively. → collimation.
Arranged in a → straight line.
Past participle of → align.
aligned magnetic field
meydân-e meqnâtisi-ye âxatidé
Fr.: champ magnétique aligné
A magnetic field whose lines of force are oriented along a particular direction or by a particular manner (axially, vertically; randomly, properly, etc.)
The fact of being in line or bringing into line.
Alioth (ε Ursae Majoris)
The brightest of the seven stars that make up the → Big Dipper → asterism. Alioth shines at magnitude +1.77 from a distance of about 80 → light-years. It is a white star of → spectral type A0pCr. The spectrum of the star is characterized by abnormally strong lines of → chromium and → europium.
Alioth, from Aliot, from Ar. Alyat (
Jown, from Ar. Jawn "black camel or horse".