enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Discriminant - Wikipedia

    en.wikipedia.org/wiki/Discriminant

    In terms of its expression as a determinant of a (2n − 1) × (2n − 1) matrix (the Sylvester matrix) divided by a n, the determinant is homogeneous of degree 2n − 1 in the entries, and dividing by a n makes the degree 2n − 2. The discriminant of a polynomial of degree n is homogeneous of degree n(n − 1) in the roots.

  3. Discriminant of an algebraic number field - Wikipedia

    en.wikipedia.org/wiki/Discriminant_of_an...

    The discriminant of K is 49 = 7 2. Accordingly, the volume of the fundamental domain is 7 and K is only ramified at 7. In mathematics, the discriminant of an algebraic number field is a numerical invariant that, loosely speaking, measures the size of the (ring of integers of the) algebraic number field.

  4. Ideal class group - Wikipedia

    en.wikipedia.org/wiki/Ideal_class_group

    The rings Z, Z, and Z, where ω is a cube root of 1 and i is a fourth root of 1 (i.e. a square root of −1), are all principal ideal domains (and in fact are all Euclidean domains), and so have class number 1: that is, they have trivial ideal class groups. If k is a field, then the polynomial ring k[X 1, X 2, X 3, ...] is an integral domain ...

  5. Cubic equation - Wikipedia

    en.wikipedia.org/wiki/Cubic_equation

    If only one root, say r 1, is real, then r 2 and r 3 are complex conjugates, which implies that r 2 – r 3 is a purely imaginary number, and thus that (r 2 – r 3) 2 is real and negative. On the other hand, r 1 – r 2 and r 1 – r 3 are complex conjugates, and their product is real and positive. [ 23 ]

  6. Algebraic number field - Wikipedia

    en.wikipedia.org/wiki/Algebraic_number_field

    For this converse the field discriminant is needed. This is the Dedekind discriminant theorem. In the example above, the discriminant of the number field () with x 3 − x − 1 = 0 is −23, and as we have seen the 23-adic place ramifies. The Dedekind discriminant tells us it is the only ultrametric place that does.

  7. Seventh grade - Wikipedia

    en.wikipedia.org/wiki/Seventh_grade

    Seventh grade (also 7th Grade or Grade 7) is the seventh year of formal or compulsory education. The seventh grade is typically the first or second year of middle school. In the United States, kids in seventh grade are usually around 12–13 years old. Different terms and numbers are used in other parts of the world.

  8. Jacobian matrix and determinant - Wikipedia

    en.wikipedia.org/wiki/Jacobian_matrix_and...

    In vector calculus, the Jacobian matrix (/ dʒ ə ˈ k oʊ b i ə n /, [1] [2] [3] / dʒ ɪ-, j ɪ-/) of a vector-valued function of several variables is the matrix of all its first-order partial derivatives.

  9. Linear discriminant analysis - Wikipedia

    en.wikipedia.org/wiki/Linear_discriminant_analysis

    Linear discriminant analysis (LDA), normal discriminant analysis (NDA), canonical variates analysis (CVA), or discriminant function analysis is a generalization of Fisher's linear discriminant, a method used in statistics and other fields, to find a linear combination of features that characterizes or separates two or more classes of objects or ...