enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Hydraulic jumps in rectangular channels - Wikipedia

    en.wikipedia.org/wiki/Hydraulic_Jumps_in...

    1. y 2 /y 1 > 1: depth increases over the jump so that y 2 > y 1 2. Fr 2 < 1: downstream flow must be subcritical 3. Fr 1 > 1: upstream flow must be supercritical. Table 2 shows the calculated values used to develop Figure 8. The values associated with a y 1 = 1.5 ft are not valid for use since they

  3. Arithmetic - Wikipedia

    en.wikipedia.org/wiki/Arithmetic

    For instance, if the number π is rounded to 4 decimal places, the result is 3.142 because the following digit is a 5, so 3.142 is closer to π than 3.141. [107] These methods allow computers to efficiently perform approximate calculations on real numbers.

  4. Equals sign - Wikipedia

    en.wikipedia.org/wiki/Equals_sign

    1 + 2 = 3, 3 + 3 = 6, 6 + 4 = 10, 10 + 5 = 15. This difficulty results from subtly different uses of the sign in education. In early, arithmetic-focused grades, the equal sign may be operational ; like the equal button on an electronic calculator, it demands the result of a calculation.

  5. Multiplication - Wikipedia

    en.wikipedia.org/wiki/Multiplication

    Area of a cloth 4.5m × 2.5m = 11.25m 2; 4 ⁠ 1 / 2 ⁠ × 2 ⁠ 1 / 2 ⁠ = 11 ⁠ 1 / 4 ⁠ Multiplication (often denoted by the cross symbol × , by the mid-line dot operator ⋅ , by juxtaposition, or, on computers, by an asterisk * ) is one of the four elementary mathematical operations of arithmetic, with the other ones being addition ...

  6. Homework - Wikipedia

    en.wikipedia.org/wiki/Homework

    Homework can take up a large portion of a student's free time and lead to stress, despair, anger, and sleep disorders among children, as well as arguments among families. Homework and its effects, justifications, motivations and alleged benefits have been the subject of sharp criticism among many education experts and researchers.

  7. Matrix (mathematics) - Wikipedia

    en.wikipedia.org/wiki/Matrix_(mathematics)

    For example, if A is a 3-by-0 matrix and B is a 0-by-3 matrix, then AB is the 3-by-3 zero matrix corresponding to the null map from a 3-dimensional space V to itself, while BA is a 0-by-0 matrix. There is no common notation for empty matrices, but most computer algebra systems allow creating and computing with them.

  8. Archimedes - Wikipedia

    en.wikipedia.org/wiki/Archimedes

    As the number of sides increases, it becomes a more accurate approximation of a circle. After four such steps, when the polygons had 96 sides each, he was able to determine that the value of π lay between 31 / 7 ⁠ (approx. 3.1429) and 3 ⁠ 10 / 71 ⁠ (approx. 3.1408), consistent with its actual value of approximately 3.1416. [71]

  9. Letter frequency - Wikipedia

    en.wikipedia.org/wiki/Letter_frequency

    The California Job Case was a compartmentalized box for printing in the 19th century, sizes corresponding to the commonality of letters. The frequency of letters in text has been studied for use in cryptanalysis, and frequency analysis in particular, dating back to the Arab mathematician al-Kindi (c. AD 801–873 ), who formally developed the method (the ciphers breakable by this technique go ...