enow.com Web Search

Search results

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

    en.wikipedia.org/wiki/Summation

    In mathematics, summation is the addition of a sequence of numbers, called addends or summands; the result is their sum or total.Beside numbers, other types of values can be summed as well: functions, vectors, matrices, polynomials and, in general, elements of any type of mathematical objects on which an operation denoted "+" is defined.

  3. Fibonacci sequence - Wikipedia

    en.wikipedia.org/wiki/Fibonacci_sequence

    Indeed, as stated above, the -th Fibonacci number equals the number of combinatorial compositions (ordered partitions) of using terms 1 and 2. It follows that the ordinary generating function of the Fibonacci sequence, ∑ i = 0 ∞ F i z i {\displaystyle \sum _{i=0}^{\infty }F_{i}z^{i}} , is the rational function z 1 − z − z 2 ...

  4. Abundance of elements in Earth's crust - Wikipedia

    en.wikipedia.org/wiki/Abundance_of_elements_in...

    Abundance (atom fraction) of the chemical elements in Earth's upper continental crust as a function of atomic number; [5] siderophiles shown in yellow Graphs of abundance against atomic number can reveal patterns relating abundance to stellar nucleosynthesis and geochemistry.

  5. Mathematics - Wikipedia

    en.wikipedia.org/wiki/Mathematics

    A Cauchy sequence consists of elements such that all subsequent terms of a term become arbitrarily close to each other as the sequence progresses (from left to right). Calculus, formerly called infinitesimal calculus, was introduced independently and simultaneously by 17th-century mathematicians Newton and Leibniz . [ 39 ]

  6. Repeating decimal - Wikipedia

    en.wikipedia.org/wiki/Repeating_decimal

    The repeating sequence of digits is called "repetend" which has a certain length greater than 0, also called "period". [5] In base 10, a fraction has a repeating decimal if and only if in lowest terms, its denominator has any prime factors besides 2 or 5, or in other words, cannot be expressed as 2 m 5 n, where m and n are non-negative integers.

  7. Waring's problem - Wikipedia

    en.wikipedia.org/wiki/Waring's_problem

    68 578 904 422 is the last known number that requires 9 fifth powers (Integer sequence S001057, Tony D. Noe, Jul 04 2017), 617 597 724 is the last number less than 1.3 × 10 9 that requires 10 fifth powers, and 51 033 617 is the last number less than 1.3 × 10 9 that requires 11.

  8. Age of the universe - Wikipedia

    en.wikipedia.org/wiki/Age_of_the_universe

    the dimmest turnoff point of main sequence stars in clusters (lower-mass stars spend a greater amount of time on the main sequence, so the lowest-mass stars that have evolved away from the main sequence set a minimum age).

  9. tf–idf - Wikipedia

    en.wikipedia.org/wiki/Tf–idf

    A high weight in tf–idf is reached by a high term frequency (in the given document) and a low document frequency of the term in the whole collection of documents; the weights hence tend to filter out common terms. Since the ratio inside the idf's log function is always greater than or equal to 1, the value of idf (and tf–idf) is greater ...