enow.com Web Search

Search results

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

    en.wikipedia.org/wiki/Complex_number

    (Here is the usual (positive) n th root of the positive real number r.) Because sine and cosine are periodic, other integer values of k do not give other values. For any , there are, in particular n distinct complex n-th roots. For example, there are 4 fourth roots of 1, namely

  3. Complex conjugate root theorem - Wikipedia

    en.wikipedia.org/wiki/Complex_conjugate_root_theorem

    It follows from the present theorem and the fundamental theorem of algebra that if the degree of a real polynomial is odd, it must have at least one real root. [2] This can be proved as follows. Since non-real complex roots come in conjugate pairs, there are an even number of them; But a polynomial of odd degree has an odd number of roots;

  4. Generalized Kac–Moody algebra - Wikipedia

    en.wikipedia.org/wiki/Generalized_Kac–Moody...

    In other words, we allow simple roots to be imaginary, whereas in a Kac–Moody algebra simple roots are always real. A generalized Kac–Moody algebra is obtained from a universal one by changing the Cartan matrix, by the operations of killing something in the center, or taking a central extension, or adding outer derivations.

  5. Complex conjugate - Wikipedia

    en.wikipedia.org/wiki/Complex_conjugate

    Geometric representation (Argand diagram) of and its conjugate ¯ in the complex plane.The complex conjugate is found by reflecting across the real axis.. In mathematics, the complex conjugate of a complex number is the number with an equal real part and an imaginary part equal in magnitude but opposite in sign.

  6. Casus irreducibilis - Wikipedia

    en.wikipedia.org/wiki/Casus_irreducibilis

    Moreover, if the polynomial degree is a power of 2 and the roots are all real, then if there is a root that can be expressed in real radicals it can be expressed in terms of square roots and no higher-degree roots, as can the other roots, and so the roots are classically constructible. Casus irreducibilis for quintic polynomials is discussed by ...

  7. Descartes' rule of signs - Wikipedia

    en.wikipedia.org/wiki/Descartes'_rule_of_signs

    The rule states that if the nonzero terms of a single-variable polynomial with real coefficients are ordered by descending variable exponent, then the number of positive roots of the polynomial is either equal to the number of sign changes between consecutive (nonzero) coefficients, or is less than it by an even number.

  8. Imaginary number - Wikipedia

    en.wikipedia.org/wiki/Imaginary_number

    An imaginary number is the product of a real number and the imaginary unit i, [note 1] which is defined by its property i 2 = −1. [1] [2] The square of an imaginary number bi is −b 2. For example, 5i is an imaginary number, and its square is −25. The number zero is considered to be both real and imaginary. [3]

  9. Ramanujan–Petersson conjecture - Wikipedia

    en.wikipedia.org/wiki/Ramanujan–Petersson...

    would have always imaginary roots from many examples. The relationship between roots and coefficients of quadratic equations leads to the third relation, called Ramanujan's conjecture. Moreover, for the Ramanujan tau function, let the roots of the above quadratic equation be α and β, then