Monday, December 4, 2017

December 04, 2017 Monday

Bedtime Story 


Origins of Trigonometric Sine


Last night we had left talking about the origins of the word Sine, one of the trigonometric functions.

Europeans had found this word “jaib” in the works of Islamic mathematicians such as Muhammad al-Khwarizmi and Al-Battani who flourished during the Golden Era of Islam.

One of the major works of Al-Battani who lived somewhere around 900 AD was Kitab-aj-Jiz or the Book of Astronomical Tables.

The Europeans had actually misread the Arabic word jyb and understandably had converted it into jaib.

Arabic mathematicians had in their turn had transliterated this word from the Hindus who had used the Sanskrit word jiva or jya as the term for sine.

The Sanskrit word translates into bowstring.

If you think that is the end of the origin of the word sine, you are mistaken.

The Hindus in their turned were inspired from Greeks word for chord who had sued the chord function that is related to the modern sine function.

The origin of tangent is pretty straight forward.

Tangent comes from the Latin word tangens which means touching as tangential line touches the circle.

Secant too has no complexity behind its origins.

Secant comes from the Latin word secans which means “cutting” as a secant cuts the circle.

The prefix “co-“ that is used in cosine, cotangent and cosecant came very late in the language of mathematics, seen for the first time in print only after 1600.

The prefix stands for complementi; thus cosine means sinus complimenti or sine of the complimentary angle.
  
Mathematical tables proved to be very useful for the rapidly industrializing European powerhouses, their utility approximating very near to the smart phones of today.  

In spite of their great utility they were very vulnerable to errors since human computers were involved, both in the transcription of the tables as well as in calculations.

This was noted by Babbage and since as we saw earlier, he was already keen on mechanization of factory production, the idea of mechanization of computation in the production of mathematical tables followed naturally.

Let me quote a small passage from the 1953 book “Faster than Thought” written by Bertram Bowden that describes very pertinently how the idea of mechanization of mathematical tables came into the mind of Charles Babbage.

“In 1812 he was sitting in his room in the Analytical Society looking at a table of logarithms, which he knew to be full of mistakes, when the idea occurred to him of computing all tabular functions by machinery.

The French government had produced several tables by a new method.”

We shall continue with this idea in the nights to come.

Stay tuned to the voice of an average story storytelling chimpanzee or login at http://panarrans.blogspot.com
                              
Good night mon ami and my fellow cousin ape.
                           
  
                

             












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Another great educator and a teacher that I am aware of is Professor Subhashish Chattopadhyay in Bangalore, India.

While I narrate stories, Professor Subhashish an electronic engineer and a former professor at BARC, does and teaches real mathematics and physics.

He started the participation of Indian students at the International Physics Olympiad.

Do visit him here:


All his books can be downloaded for free through this link:


For edutainment and English education of your children, I recommend this large collection of Halloween Songs for Kids:



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