المرجع الالكتروني للمعلوماتية
المرجع الألكتروني للمعلوماتية

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Calculators  
  
1873   01:50 صباحاً   date: 4-1-2016
Author : Before HP Calculators
Book or Source : The Museum of HP Calculators
Page and Part : ...


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Date: 30-12-2015 2154
Date: 1-1-2016 2079
Date: 11-1-2016 2126

Throughout human history man has invented devices to make repetitive tasks, such as mathematical calculation, easier. For much of history, this was difficult. The advent of methods, which progressed to machines, to help with this dilemma made life much easier for many.

Early Calculators

The first aids in counting were notched sticks and counting cords, simple tools used to retain numerical information over time and distance. These devices did not perform any mathematical operations.

A major revolution came with the abacus. This device allowed both arithmetical operations and the ability to store a fixed sum, which was represented by a given pattern of beads. The abacus, which is still in use today, was fast and extremely useful in the hands of a trained user.

The French mathematician Blaise Pascal is credited with inventing the mechanical calculator in 1642, based on a stylus and wheel design. In 1820,  based on Pascal’s design, Thomas de Colmar invented the “Arithmometer.”

         In his design, de Colmar took Pascal’s wheels and turned them on their sides. They were made wider, and tally marks were put on the outside of the drum.

The first adding machine that printed results on tape was introduced around 1872. When first introduced, many of the adding machines were hand-driven, but later models had electric motors. One of the more impressive of the early adding machines was the Burroughs Class 1/Model 9.

It was 19 inches deep, over a foot tall, and weighed more than 63 pounds.

In 1911, the Monroe LN was introduced. Previously adding machines had been separate from those that performed multiplication and division.

The Monroe LN combined these two machines into one.

As the world entered the 1950s, new progress in electronic circuitry and data processing techniques began to pave the way for reasonably sized electronic calculators. At this time, electronic adding machines were common, but most designs were based on the technology of the mechanical calculator, with electricity used to power the drum or pinwheel movement. The calculators of the 1960s were desktop sized, utilized thousands of separate

electronic components, and were costly to assemble.

Electronic Calculators

The first mass-produced electronic calculators often had retail prices of nearly one thousand dollars. The high cost was, in part, because the technology was so new, and materials were at a premium.

  A breakthrough came in 1964 when Victor Business Machines contracted with General Microelectronics to develop an integrated circuit-based desktop electronic calculator. Following this, Texas Instruments began to produce an integrated circuit-based, hand-held calculator called the “CalTech.” It performed the four basic arithmetical operations.

Modern Calculators

The calculators of today have come a long way from where they started.

Today, calculators can perform a range of complicated functions as well as basic ones. Commonly, people use calculators to ease the burden of performing routine mathematical calculations, such as balancing checkbooks.

Hand-held calculators now allow people to do calculations anywhere, with little risk of error in the results.

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Reference

Before HP Calculators. The Museum of HP Calculators. June 2001. <http://www.hp- museum.org>.




الجبر أحد الفروع الرئيسية في الرياضيات، حيث إن التمكن من الرياضيات يعتمد على الفهم السليم للجبر. ويستخدم المهندسون والعلماء الجبر يومياً، وتعول المشاريع التجارية والصناعية على الجبر لحل الكثير من المعضلات التي تتعرض لها. ونظراً لأهمية الجبر في الحياة العصرية فإنه يدرّس في المدارس والجامعات في جميع أنحاء العالم. ويُعجب الكثير من الدارسين للجبر بقدرته وفائدته الكبيرتين، إذ باستخدام الجبر يمكن للمرء أن يحل كثيرًا من المسائل التي يتعذر حلها باستخدام الحساب فقط.وجاء اسمه من كتاب عالم الرياضيات والفلك والرحالة محمد بن موسى الخورازمي.


يعتبر علم المثلثات Trigonometry علماً عربياً ، فرياضيو العرب فضلوا علم المثلثات عن علم الفلك كأنهما علمين متداخلين ، ونظموه تنظيماً فيه لكثير من الدقة ، وقد كان اليونان يستعملون وتر CORDE ضعف القوسي قياس الزوايا ، فاستعاض رياضيو العرب عن الوتر بالجيب SINUS فأنت هذه الاستعاضة إلى تسهيل كثير من الاعمال الرياضية.

تعتبر المعادلات التفاضلية خير وسيلة لوصف معظم المـسائل الهندسـية والرياضـية والعلمية على حد سواء، إذ يتضح ذلك جليا في وصف عمليات انتقال الحرارة، جريان الموائـع، الحركة الموجية، الدوائر الإلكترونية فضلاً عن استخدامها في مسائل الهياكل الإنشائية والوصف الرياضي للتفاعلات الكيميائية.
ففي في الرياضيات, يطلق اسم المعادلات التفاضلية على المعادلات التي تحوي مشتقات و تفاضلات لبعض الدوال الرياضية و تظهر فيها بشكل متغيرات المعادلة . و يكون الهدف من حل هذه المعادلات هو إيجاد هذه الدوال الرياضية التي تحقق مشتقات هذه المعادلات.