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Вопрос по математике:
найдите число прямоугольников, составленных из клеток доски с m горизонталями и n вертикалями, которые содержат клетку с кординатами (p, q)-
Автор:
zayne
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ответ по ссылке: http://math.hashcode.ru/questions/87587/комбинаторика-найти-число-прямоугольников-составленных-из-клеток-доски-с-n-вертикалями
Еще 4 ненужных тебе вопроса, но это важно для поиска
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Вопрос по английскому языку:
Нужен краткий пересказ текста. Максимально кратко, но без потери важной информации.
Let us take a look at the history of computers that we know today. The
very first calculating device used was the ten fingers of a m an’s hands. This, in
fact, is why today we still count in tens and multiples of tens.
Then the abacus was invented. People went on using some form of abacus well into the 16th century, and it is still being used in some parts of the
world because it can be understood without knowing how to read.
During the 17th and 18th centuries many people tried to find easy ways
of calculating. J. Napier, a Scotsman, invented a mechanical way of multiplying and dividing, which is now the modern slide rule works. Henry Briggs
used Napier’s ideas to produce logarithm tables which all mathematicians
use today.
Calculus, another branch of mathematics, was independently invented
by both Sir Isaak Newton, an Englishman, and Leibnitz, a German m athematician. The first real calculating machine appeared in 1820 as the result of
several people’s experiments.
In 1830 Charles Babbage, a gifted English mathematician proposed to
build a general-purpose problem-solving machine that he called “the analytical engine.” This machine, which Babbage showed at the Paris Exhibition in
1855, was an attempt to cut out the human being altogether, except for providing the machine with the necessary facts about the problem to be solved.
He never finished this work, but many of his ideas were the basis for building
today’s computers.
By the early part of the 20th century electromechanical machines had
been developed and were used for business data processing. Dr. Herman Hollerith, a young statistician from the US Census Bureau successfully tabulated
the 1890 census. Hollerith invented a means of coding the data by punching
holes into cards. He built one machine to punch the holes and others to tabulate the collected data. Later Hollerith left the Census Bureau and established his own tabulating machine company. Through a series of merges the company eventually became the IBM Corporation.
Until the middle of the 20th century machines designed to manipulate
punched card data were widely used for business data processing. These early
electromechanical data processors were called unit record machines because
each punched card contained a unit of data.
In the mid-1940s electronic computers were developed to perform
calculations for military and scientific purposes. By the end of the 1960s
commercial models of these computers were widely used for both scientific computation and business data processing. Initially these computers
accepted their input data from punched cards. By the late 1970s punched
cards had been almost universally replaced by keyboard terminals. Since
that time advances in science have led to the proliferation of computers throughout our society, and the past is but the prologue that gives us
a glimpse of the future.-
Ответов: 1
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5 лет назад
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Вопрос по английскому языку:
Нужен краткие пересказ текста, максимально коротко, но без потери важной информации. Пожалуйста.
In 1930 the first analog computer was built by American named Vannevar
Bush. This device was used in World War II to help aim guns.
Many technical developments of electronic digital computers took place
in the 1940s and 1950s. Mark I, the name given to the first digital computer,
was completed in 1944. The man responsible for this invention was Professor
Howard Aiken. This was the first machine that could figure out long lists of
mathematical problems at a very fast rate.
In 1946 two engineers at the University of Pennsilvania, J. Eckert and
J. Maushly, built their digital computer with vacuum tubes. They named
their new invention ENIAC (the Electronic Numerical Integrator and Calculator).
Another important achievement in developing computers came in 1947,
when John von Neumann developed the idea of keeping instructions for
the computer inside the computer’s memory. The contribution of John von
Neumann was particularly significant. As contrasted with Babbage’s analytical engine, which was designed to store only data, von N eum ann’s machine,
called the Electronic Discrete Variable Computer, or EDVAC, was able to
store both data and instructions. He also contributed to the idea of storing
data and instructions in a binary code that uses only ones and zeros. This
simplified computer design. Thus computers use two conditions, high voltage and low voltage, to translate the symbols by which we communicate into
unique combinations of electrical pulses. We refer to these combinations as
codes.
N eumann’s stored program computer as well as other machines of that
time were made possible by the invention of the vacuum tube that could control and amplify electronic signals. Early computers, using vacuum tubes,
could perform computations in thousandths of seconds, called milliseconds,
instead of seconds required by mechanical devices.-
Ответов: 1
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5 лет назад
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Вопрос по литературе:
2) Какие глаза были у Бульки?-
Ответов: 2
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5 лет назад
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Вопрос по физике:
Выбрать рациональное расположение шкивов на валу, если mj= 120кНМ, mp=
70 кН-М, m3= 65 кН.м.-
Ответов: 1
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5 лет назад
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