Finite differenceA finite difference is a mathematical expression of the form f (x + b) − f (x + a). If a finite difference is divided by b − a, one gets a difference quotient. The approximation of derivatives by finite differences plays a central role in finite difference methods for the numerical solution of differential equations, especially boundary value problems. The difference operator, commonly denoted is the operator that maps a function f to the function defined by A difference equation is a functional equation that involves the finite difference operator in the same way as a differential equation involves derivatives.
Inverse trigonometric functionsIn mathematics, the inverse trigonometric functions (occasionally also called arcus functions, antitrigonometric functions or cyclometric functions) are the inverse functions of the trigonometric functions (with suitably restricted domains). Specifically, they are the inverses of the sine, cosine, tangent, cotangent, secant, and cosecant functions, and are used to obtain an angle from any of the angle's trigonometric ratios. Inverse trigonometric functions are widely used in engineering, navigation, physics, and geometry.
BibliographyBibliography (from βιβλίον and -γραφία), as a discipline, is traditionally the academic study of books as physical, cultural objects; in this sense, it is also known as bibliology (from -λογία). English author and bibliographer John Carter describes bibliography as a word having two senses: one, a list of books for further study or of works consulted by an author (or enumerative bibliography); the other one, applicable for collectors, is "the study of books as physical objects" and "the systematic description of books as objects" (or descriptive bibliography).
Bibliographic databaseA bibliographic database is a database of bibliographic records. This is an organised online collection of references to published written works like journal and newspaper articles, conference proceedings, reports, government and legal publications, patents and books. In contrast to library catalogue entries, a majority of the records in bibliographic databases describe articles and conference papers rather than complete monographs, and they generally contain very rich subject descriptions in the form of keywords, subject classification terms, or abstracts.
Nowhere continuous functionIn mathematics, a nowhere continuous function, also called an everywhere discontinuous function, is a function that is not continuous at any point of its domain. If is a function from real numbers to real numbers, then is nowhere continuous if for each point there is some such that for every we can find a point such that and . Therefore, no matter how close we get to any fixed point, there are even closer points at which the function takes not-nearby values.
Italian languageItalian (italiano itaˈljaːno or lingua italiana ˈliŋɡwa itaˈljaːna) is a Romance language of the Indo-European language family that evolved from the Vulgar Latin of the Roman Empire. Together with Sardinian, Italian is the least divergent language from Latin. Spoken by about 85 million people (2022), Italian is an official language in Italy, San Marino, Switzerland (Ticino and the Grisons), and is the primary language of Vatican City. It has official minority status in Croatia and in some areas of Slovenian Istria.
CitationA citation is a reference to a source. More precisely, a citation is an abbreviated alphanumeric expression embedded in the body of an intellectual work that denotes an entry in the bibliographic references section of the work for the purpose of acknowledging the relevance of the works of others to the topic of discussion at the spot where the citation appears. Generally, the combination of both the in-body citation and the bibliographic entry constitutes what is commonly thought of as a citation (whereas bibliographic entries by themselves are not).
Law libraryA law library is a special library used by law students, lawyers, judges and their law clerks, historians and other scholars of legal history in order to research the law. Law libraries are also used by people who draft or advocate for new laws, e.g. legislators and others who work in state government, local government, and legislative counsel offices or the U.S. Office of Law Revision Counsel and lobbying professionals. Self-represented, or pro se, litigants (parties to a civil lawsuit or criminal defendants who do not have a licensed attorney representing them) also use law libraries.
Reference workA reference work is a non-fiction work, such as a paper, book or periodical (or their electronic equivalents), to which one can refer for information. The information is intended to be found quickly when needed. Such works are usually referred to for particular pieces of information, rather than read beginning to end. The writing style used in these works is informative; the authors avoid use of the first person, and emphasize facts. Indices are a common navigation feature in many types of reference works.
Fourth-generation programming languageA fourth-generation programming language (4GL) is any computer programming language that belongs to a class of languages envisioned as an advancement upon third-generation programming languages (3GL). Each of the programming language generations aims to provide a higher level of abstraction of the internal computer hardware details, making the language more programmer-friendly, powerful, and versatile. While the definition of 4GL has changed over time, it can be typified by operating more with large collections of information at once rather than focusing on just bits and bytes.