When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Proof by contradiction - Wikipedia

    en.wikipedia.org/wiki/Proof_by_contradiction

    In this general sense, proof by contradiction is also known as indirect proof, proof by assuming the opposite, [2] and reductio ad impossibile. [3] A mathematical proof employing proof by contradiction usually proceeds as follows: The proposition to be proved is P. We assume P to be false, i.e., we assume ¬P. It is then shown that ¬P implies ...

  3. Covariance and contravariance of vectors - Wikipedia

    en.wikipedia.org/wiki/Covariance_and_contra...

    tangent basis e 1, e 2, e 3 to the coordinate curves (left), dual basis, covector basis, or reciprocal basis e 1, e 2, e 3 to coordinate surfaces (right), in 3-d general curvilinear coordinates (q 1, q 2, q 3), a tuple of numbers to define a point in a position space. Note the basis and cobasis coincide only when the basis is orthonormal. [1 ...

  4. Change of basis - Wikipedia

    en.wikipedia.org/wiki/Change_of_basis

    In mathematics, an ordered basis of a vector space of finite dimension n allows representing uniquely any element of the vector space by a coordinate vector, which is a sequence of n scalars called coordinates.

  5. Faulty generalization - Wikipedia

    en.wikipedia.org/wiki/Faulty_generalization

    A faulty generalization is an informal fallacy wherein a conclusion is drawn about all or many instances of a phenomenon on the basis of one or a few instances of that phenomenon. It is similar to a proof by example in mathematics. [1] It is an example of jumping to conclusions. [2]

  6. Boolean algebra - Wikipedia

    en.wikipedia.org/wiki/Boolean_algebra

    In mathematics and mathematical logic, Boolean algebra is a branch of algebra.It differs from elementary algebra in two ways. First, the values of the variables are the truth values true and false, usually denoted 1 and 0, whereas in elementary algebra the values of the variables are numbers.

  7. Reductio ad absurdum - Wikipedia

    en.wikipedia.org/wiki/Reductio_ad_absurdum

    Reductio ad absurdum, painting by John Pettie exhibited at the Royal Academy in 1884. In logic, reductio ad absurdum (Latin for "reduction to absurdity"), also known as argumentum ad absurdum (Latin for "argument to absurdity") or apagogical argument, is the form of argument that attempts to establish a claim by showing that the opposite scenario would lead to absurdity or contradiction.

  8. Orientation (vector space) - Wikipedia

    en.wikipedia.org/wiki/Orientation_(vector_space)

    For example, the standard basis on R n provides a standard orientation on R n (in turn, the orientation of the standard basis depends on the orientation of the Cartesian coordinate system on which it is built). Any choice of a linear isomorphism between V and R n will then provide an orientation on V. The ordering of elements in a basis is crucial.

  9. Basis (universal algebra) - Wikipedia

    en.wikipedia.org/wiki/Basis_(universal_algebra)

    A basis (or reference frame) of a (universal) algebra is a function that takes some algebra elements as values () and satisfies either one of the following two equivalent conditions. Here, the set of all () is called the basis set, whereas several authors call it the "basis".