Constant

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A constant is something that does not change, over time or otherwise: a fixed value. In most fields of discourse the term is an antonym of "variable", but in mathematical parlance a mathematical variable may sometimes also be called a constant.

Contents 1 In mathematics and computer science 2 In physics and chemistry 3 For people 4 Other

More particularly, the term constant has several uses:

[edit] In mathematics and computer science

• Mathematical constant, a number that arises naturally in mathematics, such as π and e
• A coefficient or other parameter in a formula, given as a number or as a variable, but not being considered one of the arguments
• The constant term of a polynomial, which is the term of degree 0
• A constant function, a function that maps all arguments to one same value
• The constant of integration, usually denoted by C, expressing a free parameter arising in integration
• Logical constant, a symbol in symbolic logic that has the same meaning in all models, such as the symbol "=" for "equals".
• Constant (computer science), a variable whose value cannot be changed once it is initially bound to a value
• Constant time, or O(1) time, in computational complexity theory, meaning a computation time needed for solving a problem that does not depend on the size of the input data
• Exact trigonometric constants

[edit] In physics and chemistry

• Physical constant, a physical quantity that is generally believed to be both universal in nature and constant in time, such as c, the speed of light, or h, the Planck constant
• Cosmological constant, usually denoted by Λ, a parameter modifying the original equations of the theory of general relativity, introduced by Einstein and important for determining the ultimate fate of the universe as predicted by the theory
• Time constant, usually denoted by τ, a value characterizing the frequency response of a first-order, linear time-invariant system
• Reaction rate constant, often denoted k or λ, a value characterizing the speed of a chemical reaction

[edit] For people

• Constant (given name), a given name
• Constant (surname), a surname
• Constans, a Roman Emperor who ruled from 337 to 350
• Constant Nieuwenhuys, painter and member of the Situationist International

[edit] Other

• USS Constant
• The Constant, an episode of the Lost TV series
• Constants, a post-rock band from Amherst, MA who tour using a school bus converted to run on vegetable oil.

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