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Mathematics is a field of study that discovers and organizes methods, theories and theorems that are developed and proved for the needs of empirical sciences and mathematics itself. There are many areas of mathematics, which include number theory (the study of numbers), algebra (the study of formulas and related struct... |
division into four main areas—arithmetic, geometry, algebra, and calculus—endured until the end of the 19th century. Areas such as celestial mechanics and solid mechanics were then studied by mathematicians, but now are considered as belonging to physics. The subject of combinatorics has been studied for much of record... |
other subfields. A fundamental innovation was the ancient Greeks' introduction of the concept of proofs, which require that every assertion must be proved. For example, it is not sufficient to verify by measurement that, say, two lengths are equal; their equality must be proven via reasoning from previously accepted re... |
necessarily embedded in a larger space. Riemannian geometry, the study of distance properties in curved spaces. Algebraic geometry, the study of curves, surfaces, and their generalizations, which are defined using polynomials. Topology, the study of properties that are kept under continuous deformations. Algebraic topo... |
of computers The study of types of algebraic structures as mathematical objects is the purpose of universal algebra and category theory. The latter applies to every mathematical structure (not only algebraic ones). At its origin, it was introduced, together with homological algebra for allowing the algebraic study of n... |
of the 19th century. Before this period, sets were not considered to be mathematical objects, and logic, although used for mathematical proofs, belonged to philosophy and was not specifically studied by mathematicians. Before Cantor's study of infinite sets, mathematicians were reluctant to consider actually infinite c... |
with random sampling or randomized experiments. Statistical theory studies decision problems such as minimizing the risk (expected loss) of a statistical action, such as using a procedure in, for example, parameter estimation, hypothesis testing, and selecting the best. In these traditional areas of mathematical statis... |
seasons, or years. Evidence for more complex mathematics does not appear until around 3000 BC, when the Babylonians and Egyptians began using arithmetic, algebra, and geometry for taxation and other financial calculations, for building and construction, and for astronomy. The oldest mathematical texts from Mesopotamia ... |
available in Europe. During the early modern period, mathematics began to develop at an accelerating pace in Western Europe, with innovations that revolutionized mathematics, such as the introduction of variables and symbolic notation by François Viète (1540–1603), the introduction of logarithms by John Napier in 1614,... |
idealized objects and how they interact. It is based on rigorous definitions that provide a standard foundation for communication. An axiom or postulate is a mathematical statement that is taken to be true without need of proof. If a mathematical statement has yet to be proven (or disproven), it is termed a conjecture.... |
evidence. === Pure and applied mathematics === Until the 19th century, the development of mathematics in the West was mainly motivated by the needs of technology and science, and there was no clear distinction between pure and applied mathematics. For example, the natural numbers and arithmetic were introduced for the ... |
and first made explicit by physicist Eugene Wigner. It is the fact that many mathematical theories (even the "purest") have applications outside their initial object. These applications may be completely outside their initial area of mathematics, and may concern physical phenomena that were completely unknown when the ... |
diffusion, or to assess climate change. The dynamics of a population can be modeled by coupled differential equations, such as the Lotka–Volterra equations. Statistical hypothesis testing, is run on data from clinical trials to determine whether a new treatment works. Since the start of the 20th century, chemistry has ... |
their possible philosophical opinions, modern mathematicians may be generally considered as Platonists, since they think of and talk of their objects of study as real objects. Armand Borel summarized this view of mathematics reality as follows, and provided quotations of G. H. Hardy, Charles Hermite, Henri Poincaré and... |
validity relies on a proof, that is, a purely-logical deduction. === Rigor === Mathematical reasoning requires rigor. This means that the definitions must be absolutely unambiguous and the proofs must be reducible to a succession of applications of inference rules, without any use of empirical evidence and intuition. R... |
early as the second millennium BCE in ancient Babylonia. Comparable evidence has been unearthed for scribal mathematics training in the ancient Near East and then for the Greco-Roman world starting around 300 BCE. The oldest known mathematics textbook is the Rhind papyrus, dated from c. 1650 BCE in Egypt. Due to a scar... |
mathematicians can see their activity as a game, more specifically as solving puzzles. This aspect of mathematical activity is emphasized in recreational mathematics. Mathematicians can find an aesthetic value to mathematics. Like beauty, it is hard to define, it is commonly related to elegance, which involves qualitie... |
years (except around World War II) to up to four individuals. It is considered the mathematical equivalent of the Nobel Prize. Other prestigious mathematics awards include: The Abel Prize, instituted in 2002 and first awarded in 2003 The Chern Medal for lifetime achievement, introduced in 2009 and first awarded in 2010... |
Algebra is a branch of mathematics that deals with abstract systems, known as algebraic structures, and the manipulation of expressions within those systems. It is a generalization of arithmetic that introduces variables and algebraic operations other than the standard arithmetic operations, such as addition and multip... |
quantities in the form of variables in addition to numbers. A higher level of abstraction is found in abstract algebra, which is not limited to a particular domain and examines algebraic structures such as groups and rings. It extends beyond typical arithmetic operations by also covering other types of operations. Univ... |
equation 2 × 3 = 3 × 2 {\displaystyle 2\times 3=3\times 2} belongs to arithmetic and expresses an equality only for these specific numbers. By replacing the numbers with variables, it is possible to express a general law that applies to any possible combination of numbers, like the commutative property of multiplicatio... |
transforming and manipulating statements according to certain rules. A key principle guiding this process is that whatever operation is applied to one side of an equation also needs to be done to the other side. For example, if one subtracts 5 from the left side of an equation one also needs to subtract 5 from the righ... |
each other, like x 4 + 3 x y 2 + 5 x 3 − 1 {\displaystyle x^{4}+3xy^{2}+5x^{3}-1} . Each term is either a constant, a variable, or a product of a constant and variables. Each variable can be raised to a positive integer power. A monomial is a polynomial with one term while two- and three-term polynomials are called ... |
+ . . . + a n x n = b {\displaystyle a_{1}x_{1}+a_{2}x_{2}+...+a_{n}x_{n}=b} , where a 1 {\displaystyle a_{1}} , a 2 {\displaystyle a_{2}} , ..., a n {\displaystyle a_{n}} and b {\displaystyle b} are constants. Examples are x 1 − 7 x 2 + 3 x 3 = 0 {\displaystyle x_{1}-7x_{2}+3x_{3}=0} and 1 4 x − y = 4 {\displ... |
vectors and linear maps can be represented by matrices. It follows that the theories of matrices and finite-dimensional vector spaces are essentially the same. In particular, vector spaces provide a third way for expressing and manipulating systems of linear equations. From this perspective, a matrix is a representatio... |
operation. The underlying set can contain mathematical objects other than numbers, and the operations are not restricted to regular arithmetic operations. For instance, the underlying set of the symmetry group of a geometric object is made up of geometric transformations, such as rotations, under which the object remai... |
and are named and generally denoted similarly. A ring is a commutative group under addition: the addition of the ring is associative, commutative, and has an identity element and inverse elements. The multiplication is associative and distributive with respect to addition; that is, a ( b + c ) = a b + a c {\displaystyl... |
( y ) {\displaystyle h(x\circ y)=h(x)\star h(y)} . The existence of a homomorphism reveals that the operation ⋆ {\displaystyle \star } in the second algebraic structure plays the same role as the operation ∘ {\displaystyle \circ } does in the first algebraic structure. Isomorphisms are a special type of homomorphism t... |
exists a morphism from object a {\displaystyle a} to object b {\displaystyle b} , and another morphism from object b {\displaystyle b} to object c {\displaystyle c} , then there must also exist one from object a {\displaystyle a} to object c {\displaystyle c} . Composition of morphisms is required to be associ... |
methods that can be used to manipulate linear and quadratic equations by "reducing" and "balancing" both sides. Other influential contributions to algebra came from the Arab mathematician Thābit ibn Qurra also in the 9th century and the Persian mathematician Omar Khayyam in the 11th and 12th centuries. In India, Brahma... |
basis of arbitrary algebraic operations. The invention of new algebraic systems based on different operations and elements accompanied this development, such as Boolean algebra, vector algebra, and matrix algebra. Influential early developments in abstract algebra were made by the German mathematicians David Hilbert, E... |
on algebraic theories such as group theory to classify topological spaces. For example, homotopy groups classify topological spaces based on the existence of loops or holes in them. Number theory is concerned with the properties of and relations between integers. Algebraic number theory applies algebraic methods and pr... |
algebraic expressions are often difficult to solve directly. Instead, students need to learn how to transform them according to certain laws, often to determine an unknown quantity. Some tools to introduce students to the abstract side of algebra rely on concrete models and visualizations of equations, including geomet... |
In mathematics, an algebraic expression is an expression built up from constants (usually, algebraic numbers), variables, and the basic algebraic operations: addition (+), subtraction (-), multiplication (×), division (÷), whole number powers, and roots (fractional powers).. For example, 3 x 2 − 2 x y + c {\displayst... |
not exist for all such equations (just for some of them) if n ≥ {\displaystyle \geq } 5. == Rational expressions == Given two polynomials P ( x ) {\displaystyle P(x)} and Q ( x ) {\displaystyle Q(x)} , their quotient is called a rational expression or simply rational fraction. A rational expression P ( x ) Q ( ... |
according to common but not universal conventions. A rational algebraic expression (or rational expression) is an algebraic expression that can be written as a quotient of polynomials, such as x2 + 4x + 4. An irrational algebraic expression is one that is not rational, such as √x + 4. == See also == Algebraic function ... |
A solution in radicals or algebraic solution is an expression of a solution of a polynomial equation that is algebraic, that is, relies only on addition, subtraction, multiplication, division, raising to integer powers, and extraction of nth roots (square roots, cube roots, etc.). A well-known example is the quadratic ... |
Multilinear algebra is the study of functions with multiple vector-valued arguments, with the functions being linear maps with respect to each argument. It involves concepts such as matrices, tensors, multivectors, systems of linear equations, higher-dimensional spaces, determinants, inner and outer products, and dual ... |
In mathematics and theoretical computer science, a type theory is the formal presentation of a specific type system. Type theory is the academic study of type systems. Some type theories serve as alternatives to set theory as a foundation of mathematics. Two influential type theories that have been proposed as foundati... |
as Lawvere's Elementary Theory of the Category of Sets (ETCS). Homotopy type theory continues in this line using type theory. Researchers are exploring connections between dependent types (especially the identity type) and algebraic topology (specifically homotopy). === Proof assistants === Much of the current research... |
\langle e,t\rangle ,t\rangle } is a function from sets of entities to truth-values, i.e. a (indicator function of a) set of sets. This latter type is standardly taken to be the type of natural language quantifiers, like everybody or nobody (Montague 1973, Barwise and Cooper 1981). Type theory with records is a formal s... |
are formally written with the turnstile symbol ⊢ {\displaystyle \vdash } . x : b o o l , y : n a t ⊢ ( if x y y ) : n a t {\displaystyle x:{\mathsf {bool}},y:{\mathsf {nat}}\vdash ({\textrm {if}}\,x\,y\,y):{\mathsf {nat}}} If there are no assumptions, there will be nothing to the left of the turnstile. ⊢ S : n a t → n ... |
Given a context Γ {\displaystyle \Gamma } and a type τ {\displaystyle \tau } , decide whether there exists a term t {\displaystyle t} that can be assigned the type τ {\displaystyle \tau } in the type environment Γ {\displaystyle \Gamma } . Girard's paradox shows that type inhabitation is strongly related to the consist... |
theory, by rule or assumption. However, terms may not compute down to canonical terms and it will interfere with the ability to determine if two terms are judgementally equal to each other. ==== Constructive mathematics ==== Per Martin-Löf proposed his intuitionistic type theory as a foundation for constructive mathema... |
related to category theory than it is to set theory." In brief, a category can be viewed as a type theory by regarding its objects as types (or sorts ), i.e. "Roughly speaking, a category may be thought of as a type theory shorn of its syntax." A number of significant results follow in this way: cartesian closed catego... |
t ) {\displaystyle \mathrm {add} :{\mathsf {nat}}\to ({\mathsf {nat}}\to {\mathsf {nat}})} Strictly speaking, a simple type only allows for one input and one output, so a more faithful reading of the above type is that a d d {\displaystyle \mathrm {add} } is a function which takes in a natural number and returns a func... |
{\displaystyle s} is a term of type σ {\displaystyle \sigma } , then the application of t {\displaystyle t} to s {\displaystyle s} , often written ( t s ) {\displaystyle (t\,s)} , has type τ {\displaystyle \tau } . For example, if one knows the type notations 0 : nat {\displaystyle 0:{\textsf {nat}}} , 1 : nat {\displa... |
{add} \,x\,x)\,2\rightarrow \mathrm {add} \,2\,2} In type theories that also establish notions of equality for types and terms, there are corresponding inference rules of β {\displaystyle \beta } -equality and η {\displaystyle \eta } -equality. === Common terms and types === ==== Empty type ==== The empty type has no t... |
s , t ) {\displaystyle (s,t)} has the product type σ × τ {\displaystyle \sigma \times \tau } , where σ {\displaystyle \sigma } is the type of s {\displaystyle s} and τ {\displaystyle \tau } is the type of t {\displaystyle t} . Each product type is then usually defined with eliminator functions f i r s t : σ × τ → σ {\d... |
term of type a {\displaystyle a} , and returns the list with the element at the end. The type annotation of such a function would be a p p e n d : ∀ a . l i s t a → a → l i s t a {\displaystyle \mathrm {append} :\forall \,a.{\mathsf {list}}\,a\to a\to {\mathsf {list}}\,a} , which can be read as "for any type a {\displa... |
{vector}}\,n} , where n {\displaystyle n} is a term of type n a t {\displaystyle {\mathsf {nat}}} encoding the length of the vector. This allows for greater specificity and type safety: functions with vector length restrictions or length matching requirements, such as the dot product, can encode this requirement as par... |
equivalence that type theory already provides. An identity type requires two terms of the same type and is written with the symbol = {\displaystyle =} . For example, if x + 1 {\displaystyle x+1} and 1 + x {\displaystyle 1+x} are terms, then x + 1 = 1 + x {\displaystyle x+1=1+x} is a possible type. Canonical terms are c... |
lambda terms. In set theory, "1+1=2" means that "1+1" is just another way to refer the value "2". Type theory's computation does require a complicated concept of equality. Set theory encodes numbers as sets. Type theory can encode numbers as functions using Church encoding, or more naturally as inductive types, and the... |
theory, where the property holds without needing an axiom. "Law of Excluded Middle" is often added to satisfy users who want classical logic, instead of intuitionistic logic. The Axiom of Choice does not need to be added to type theory, because in most type theories it can be derived from the rules of inference. This i... |
In mathematics, a polynomial is a mathematical expression consisting of indeterminates (also called variables) and coefficients, that involves only the operations of addition, subtraction, multiplication and exponentiation to nonnegative integer powers, and has a finite number of terms. An example of a polynomial of a ... |
convention, the result of substituting a for x in P. Thus, the polynomial P defines the function a ↦ P ( a ) , {\displaystyle a\mapsto P(a),} which is the polynomial function associated to P. Frequently, when using this notation, one supposes that a is a number. However, one may use it over any domain where addition an... |
number of indeterminates, raised to non-negative integer powers. == Classification == The exponent on an indeterminate in a term is called the degree of that indeterminate in that term; the degree of the term is the sum of the degrees of the indeterminates in that term, and the degree of a polynomial is the largest deg... |
In the case of polynomials in more than one indeterminate, a polynomial is called homogeneous of degree n if all of its non-zero terms have degree n. The zero polynomial is homogeneous, and, as a homogeneous polynomial, its degree is undefined. For example, x3y2 + 7x2y3 − 3x5 is homogeneous of degree 5. For more detail... |
and z", listing the indeterminates allowed. == Operations == === Addition and subtraction === Polynomials can be added using the associative law of addition (grouping all their terms together into a single sum), possibly followed by reordering (using the commutative law) and combining of like terms. For example, if P =... |
P Q = 4 x 2 + ( 10 x y + 6 x y + 5 x y ) + 2 x 2 y + ( 2 x + 10 x ) + 15 y 2 + 3 x y 2 + ( 3 y + 25 y ) + 5 {\displaystyle {\begin{array}{rcccrcrcrcr}PQ&=&&4x^{2}&+&(10xy+6xy+5xy)&+&2x^{2}y&+&(2x+10x)\\&&+&15y^{2}&+&3xy^{2}&+&(3y+25y)&+&5\end{array}}} which can be simplified to P Q = 4 x 2 + 21 x y + 2 x 2 y + 12 x + 1... |
(for example, the integers or a field) also have a factored form in which the polynomial is written as a product of irreducible polynomials and a constant. This factored form is unique up to the order of the factors and their multiplication by an invertible constant. In the case of the field of complex numbers, the irr... |
integers modulo p, the derivative of the polynomial xp + x is the polynomial 1. == Polynomial functions == A polynomial function is a function that can be defined by evaluating a polynomial. More precisely, a function f of one argument from a given domain is a polynomial function if there exists a polynomial a n x n + ... |
degree 0 polynomial is a horizontal line with y-intercept a0 The graph of a degree 1 polynomial (or linear function) is an oblique line with y-intercept a0 and slope a1. The graph of a degree 2 polynomial is a parabola. The graph of a degree 3 polynomial is a cubic curve. The graph of any polynomial with degree 2 or gr... |
of a polynomial P if and only if the linear polynomial x − a divides P, that is if there is another polynomial Q such that P = (x − a) Q. It may happen that a power (greater than 1) of x − a divides P; in this case, a is a multiple root of P, and otherwise a is a simple root of P. If P is a nonzero polynomial, there is... |
and showed that for each equation, one may decide whether it is solvable by radicals, and, if it is, solve it. This result marked the start of Galois theory and group theory, two important branches of modern algebra. Galois himself noted that the computations implied by his method were impracticable. Nevertheless, form... |
linear combinations are called polynomials. For complex coefficients, there is no difference between such a function and a finite Fourier series. Trigonometric polynomials are widely used, for example in trigonometric interpolation applied to the interpolation of periodic functions. They are also used in the discrete F... |
and R [ x 1 , … , x n ] {\displaystyle R[x_{1},\ldots ,x_{n}]} in the multivariate case. One has R [ x 1 , … , x n ] = ( R [ x 1 , … , x n − 1 ] ) [ x n ] . {\displaystyle R[x_{1},\ldots ,x_{n}]=\left(R[x_{1},\ldots ,x_{n-1}]\right)[x_{n}].} So, most of the theory of the multivariate case can be reduced to an iterated ... |
if there exists a polynomial q in R[x] such that f q = g. If a ∈ R , {\displaystyle a\in R,} then a is a root of f if and only x − a {\displaystyle x-a} divides f. In this case, the quotient can be computed using the polynomial long division. If F is a field and f and g are polynomials in F[x] with g ≠ 0, then there ex... |
r's are integers such that 0 < rm < b and 0 ≤ ri < b for i = 0, 1, . . . , m − 1. === Interpolation and approximation === The simple structure of polynomial functions makes them quite useful in analyzing general functions using polynomial approximations. An important example in calculus is Taylor's theorem, which rough... |
== References == == External links == Markushevich, A.I. (2001) [1994], "Polynomial", Encyclopedia of Mathematics, EMS Press "Euler's Investigations on the Roots of Equations". Archived from the original on September 24, 2012. |
In mathematics, an algebra over a field (often simply called an algebra) is a vector space equipped with a bilinear product. Thus, an algebra is an algebraic structure consisting of a set together with operations of multiplication and addition and scalar multiplication by elements of a field and satisfying the axioms i... |
· y). These three axioms are another way of saying that the binary operation is bilinear. An algebra over K is sometimes also called a K-algebra, and K is called the base field of A. The binary operation is often referred to as multiplication in A. The convention adopted in this article is that multiplication of elemen... |
L, then this would define a right ideal. A two-sided ideal is a subset that is both a left and a right ideal. The term ideal on its own is usually taken to mean a two-sided ideal. Of course when the algebra is commutative, then all of these notions of ideal are equivalent. Conditions (1) and (2) together are equivalent... |
and w {\displaystyle w} in V {\displaystyle V} . So, if k 1 , k 2 ∈ K {\displaystyle k_{1},k_{2}\in K} and v 1 , v 2 ∈ V {\displaystyle v_{1},v_{2}\in V} , one has ( k 1 + v 1 ) ( k 2 + v 2 ) = k 1 k 2 + ( k 1 v 2 + k 2 v 1 ) . {\displaystyle (k_{1}+v_{1})(k_{2}+v_{2})=k_{1}k_{2}+(k_{1}v_{2}+k_{2}v_{1})... |
algebra === A non-associative algebra (or distributive algebra) over a field K is a K-vector space A equipped with a K-bilinear map A × A → A {\displaystyle A\times A\rightarrow A} . The usage of "non-associative" here is meant to convey that associativity is not assumed, but it does not mean it is prohibited – that is... |
the structure coefficients are generally written with upper and lower indices, so as to distinguish their transformation properties under coordinate transformations. Specifically, lower indices are covariant indices, and transform via pullbacks, while upper indices are contravariant, transforming under pushforwards. Th... |
is common to consider the more general concept of an algebra over a ring, where a commutative ring R replaces the field K. The only part of the definition that changes is that A is assumed to be an R-module (instead of a K-vector space). === Associative algebras over rings === A ring A is always an associative algebra ... |
In mathematics, a quartic equation is one which can be expressed as a quartic function equaling zero. The general form of a quartic equation is a x 4 + b x 3 + c x 2 + d x + e = 0 {\displaystyle ax^{4}+bx^{3}+cx^{2}+dx+e=0\,} where a ≠ 0. The quartic is the highest order polynomial equation that can be solved by radica... |
−1 is a root. In either case the full quartic can then be divided by the factor (x − 1) or (x + 1) respectively yielding a new cubic polynomial, which can be solved to find the quartic's other roots. If a 1 = a 0 k , {\displaystyle \ a_{1}=a_{0}k\ ,} a 2 = 0 {\displaystyle \ a_{2}=0\ } and a 4 = a 3 k , {\displaystyle ... |
+ a 1 ( x + m / x ) + a 2 = 0 {\displaystyle a_{0}(x^{2}+m^{2}/x^{2})+a_{1}(x+m/x)+a_{2}=0} , a 0 ( z 2 − 2 m ) + a 1 ( z ) + a 2 = 0 {\displaystyle a_{0}(z^{2}-2m)+a_{1}(z)+a_{2}=0} , z 2 + ( a 1 / a 0 ) z + ( a 2 / a 0 − 2 m ) = 0 {\displaystyle z^{2}+(a_{1}/a_{0})z+(a_{2}/a_{0}-2m)=0} (a quadratic in z = x + m/x) ==... |
3 {\displaystyle q={\frac {b^{3}-4abc+8a^{2}d}{8a^{3}}}} r = 16 a b 2 c − 64 a 2 b d − 3 b 4 + 256 a 3 e 256 a 4 {\displaystyle r={\frac {16ab^{2}c-64a^{2}bd-3b^{4}+256a^{3}e}{256a^{4}}}} , Then, the criteria to identify a priori each case of quartic equations with multiple roots and their respective solutions are show... |
s 1 ± 2 ( s 2 − ξ q s 1 ) ] − b 4 a {\displaystyle x={\frac {1}{2}}\left[\xi {\sqrt {s_{1}}}\pm {\sqrt {2{\biggl (}s_{2}-{\frac {\xi q}{\sqrt {s_{1}}}}{\biggr )}}}\right]-{\frac {b}{4a}}} , where: s 1 = 9 q 2 − 32 p r p 2 + 12 r > 0 {\displaystyle s_{1}={\frac {9q^{2}-32pr}{p^{2}+12r}}>0} s 2 = − 2 p ( p 2 − 4 r ) + 9 ... |
C B 2 16 A 3 − B D 4 A 2 + E A ) = 0 . {\displaystyle \ u^{4}+\left({-3B^{2} \over 8A^{2}}+{C \over A}\right)u^{2}+\left({B^{3} \over 8A^{3}}-{BC \over 2A^{2}}+{D \over A}\right)u+\left({-3B^{4} \over 256A^{4}}+{CB^{2} \over 16A^{3}}-{BD \over 4A^{2}}+{E \over A}\right)=0\ .} Now rename the coefficients of u. Let a = −... |
− a ) u 2 − b u + b 2 4 ( 2 y − a ) = ( 2 y − a u − b 2 2 y − a ) 2 . {\displaystyle (u^{2}+y)^{2}=u^{4}+2yu^{2}+y^{2}=(2y-a)u^{2}-bu+(y^{2}-c)=(2y-a)u^{2}-bu+{\frac {b^{2}}{\ 4(2y-a)\ }}=\left({\sqrt {2y-a\ }}\,u-{\frac {b}{2{\sqrt {2y-a\ }}}}\right)^{2}\ .} Subtracting, we get the difference of two squares which is t... |
means of a method discovered by Lodovico Ferrari. Once the depressed quartic has been obtained, the next step is to add the valid identity ( u 2 + a ) 2 − u 4 − 2 a u 2 = a 2 {\displaystyle \left(u^{2}+a\right)^{2}-u^{4}-2au^{2}=a^{2}} to equation (1), yielding The effect has been to fold up the u4 term into a perfect ... |
2 y + a ) ( y 2 + 2 y a + a 2 − c ) = 0. {\displaystyle (-b)^{2}-4\left(2y+a\right)\left(y^{2}+2ya+a^{2}-c\right)=0.\,} Multiply the binomial with the polynomial, b 2 − 4 ( 2 y 3 + 5 a y 2 + ( 4 a 2 − 2 c ) y + ( a 3 − a c ) ) = 0 {\displaystyle b^{2}-4\left(2y^{3}+5ay^{2}+\left(4a^{2}-2c\right)y+\left(a^{3}-ac\right)\... |
± s b 2 a + 2 y ) 2 . {\displaystyle u={\frac {\pm _{s}{\sqrt {a+2y}}\pm _{t}{\sqrt {(a+2y)-4\left(a+y\pm _{s}{b \over 2{\sqrt {a+2y}}}\right)}}}{2}}.} Simplifying, one gets u = ± s a + 2 y ± t − ( 3 a + 2 y ± s 2 b a + 2 y ) 2 . {\displaystyle u={\pm _{s}{\sqrt {a+2y}}\pm _{t}{\sqrt {-\left(3a+2y\pm _{s}{2b \over {\sq... |
must have the same sign, the ±t is independent. To get all roots, compute x for (±s,±t) = (+,+); (+,−); (−,+); (−,−). This formula handles repeated roots without problem. Ferrari was the first to discover one of these labyrinthine solutions. The equation which he solved was x 4 + 6 x 2 − 60 x + 36 = 0 {\displaystyle x^... |
⋆ = x 2 − 2 Re ( x 1 ) x + [ Re ( x 1 ) ] 2 + [ Im ( x 1 ) ] 2 . {\displaystyle {\begin{aligned}(x-x_{1})(x-x_{2})&=x^{2}-(x_{1}+x_{1}^{\star })x+x_{1}x_{1}^{\star }\\&=x^{2}-2\operatorname {Re} (x_{1})x+[\operatorname {Re} (x_{1})]^{2}+[\operatorname {Im} (x_{1})]^{2}.\end{aligned}}} Let a = − 2 Re ( x 1 ) , {... |
This is harder to solve than it looks, but if we start again with a depressed quartic where b = 0 {\displaystyle b=0} , which can be obtained by substituting ( x − b / 4 ) {\displaystyle (x-b/4)} for x {\displaystyle x} , then r = − p {\displaystyle r=-p} , and: c + p 2 = s + q d / p = s − q e = s q {\displaystyle {\be... |
{\displaystyle A+B} as known, A {\displaystyle A} is to be obtained from the quadratic equation 2 ( A + B ) A 2 − 2 ( A + B ) 2 A − a 2 ( A + B ) − a 1 = 0 {\displaystyle 2(A+B)A^{2}-2(A+B)^{2}A-a_{2}(A+B)-a_{1}=0} Solving the resulting quadratic equation for y 2 {\displaystyle y^{2}} gives two values for y 2 {\display... |
that b = 0, is equal to z 6 + 2 c z 4 + ( c 2 − 4 e ) z 2 − d 2 ( 3 ) {\displaystyle z^{6}+2cz^{4}+\left(c^{2}-4e\right)z^{2}-d^{2}\qquad (3)} This polynomial is of degree six, but only of degree three in z2, and so the corresponding equation is solvable. By trial we can determine which three roots are the correct ones... |
Commutative algebra, first known as ideal theory, is the branch of algebra that studies commutative rings, their ideals, and modules over such rings. Both algebraic geometry and algebraic number theory build on commutative algebra. Prominent examples of commutative rings include polynomial rings; rings of algebraic int... |
of Hilbert's student Emanuel Lasker, who introduced primary ideals and proved the first version of the Lasker–Noether theorem. The main figure responsible for the birth of commutative algebra as a mature subject was Wolfgang Krull, who introduced the fundamental notions of localization and completion of a ring, as well... |
as the intersection of finitely many primary ideals. The Lasker–Noether theorem, given here, may be seen as a certain generalization of the fundamental theorem of arithmetic: For any primary decomposition of I, the set of all radicals, that is, the set {Rad(Q1), ..., Rad(Qt)} remains the same by the Lasker–Noether theo... |
rings and their quotients, used in the definition of algebraic varieties) has always been a part of algebraic geometry. However, in the late 1950s, algebraic varieties were subsumed into Alexander Grothendieck's concept of a scheme. Their local objects are affine schemes or prime spectra, which are locally ringed space... |
Texts in Mathematics. Vol. 28. Springer. ISBN 978-0-387-90171-8. Zariski, Oscar; Samuel, Pierre (1975). Vol II. Vol. 29. Springer. ISBN 978-0-387-90089-6. |
An independent equation is an equation in a system of simultaneous equations which cannot be derived algebraically from the other equations. The concept typically arises in the context of linear equations. If it is possible to duplicate one of the equations in a system by multiplying each of the other equations by some... |
Coding theory is the study of the properties of codes and their respective fitness for specific applications. Codes are used for data compression, cryptography, error detection and correction, data transmission and data storage. Codes are studied by various scientific disciplines—such as information theory, electrical ... |
can be seen as a random variable X : Ω → X {\displaystyle X:\Omega \to {\mathcal {X}}} , where x ∈ X {\displaystyle x\in {\mathcal {X}}} appears with probability P [ X = x ] {\displaystyle \mathbb {P} [X=x]} . Data are encoded by strings (words) over an alphabet Σ {\displaystyle \Sigma } . A code is a function C : X → ... |
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