Where does pi come from?Date: 13 Jan 1995 13:17:34 -0500 From: Kavita George Subject: (none) I was wondering how exactly the math notation pi was derived and whoever derived it, why did he make up that symbol for pi? Please answer this small question of mine by Jan 17. and mail it to kgeorge@walrus.mvhs.edu Sincerely Ms. Kavita George Monta Vista High School - kgeorge@walrus.mvhs.edu Date: 14 Jan 1995 00:37:37 -0500 From: Dr. Ken Subject: Re: your mail Hello there! The the Greek letter {Pi} (when I write that, I mean the symbol that you're used to seeing for Pi) was first used by a man named William Jones in 1706. He lived in England at the same time as Isaac Newton (who also lived in England), and he used the symbol {Pi} in a book called "A New Introduction to the Mathematics." He said that the work was intended "for the Use of some Friends who have neither Leisure, Convenience, nor, perhaps, Patience, to search into so many different Authors, and turn over so many tedious Volumes, as is unavoidably required to make but tolerable progress in the Mathematics." The Greek letter {Pi} is pronounced like a p in English. So it is widely believed, both in light of that fact, and in the way that Jones used it in his work, that {Pi} was used as an abbreviation for the English word "periphery." He used the word periphery the same way we now use circumference and perimeter for the distance around a circle and a polygon. However, Williams Jones was no heavyweight in the math world, and nobody really paid much attention to his use of the letter {Pi}. It wasn't until 1737 that Leonhard Euler (a big math heavyweight - one of the most revolutionary mathematicians who ever lived) used it, and then it gained pretty wide acceptance. I got most of my information from the book "A History of Pi" by Petr Beckmann, and if you're interested in learning more about Pi, I recommend you check it out. Thanks for asking! -Ken "Dr." Math __________ Date: 14 Jan 1995 00:42:05 -0500 From: Dr. Ken Subject: Re: where did Pi come from? Hello there! Here's some more information on Pi that we (actually, that Ausgezeichnet math doctor Sydney wrote it by herself) gave as an answer to a previous question. Enjoy! __________ Date: Mon, 5 Dec 1994 15:09:11 -0500 (EST) From: Dr. Sydney Subject: Re: question Pi is defined to be the ratio of the circumference of a circle to the diameter of a circle. Say you have a circle of radius 1. Then the circumference of the circle is 2Pi(1) and the diameter is 2(1), so the ratio of the circumference to the diameter is Pi. Anyway, Pi is an infinite decimal that is approximately equal to 3.14. People have worked on approximating Pi for thousands of years. For instance, Archimedes approximated Pi by inscribing polygons in the circle and taking the ratio of the circumference of the polygon to the radius of the circle (which is also the "radius" of the polygon). The more sides on the polygon, the more accurate the approximation. So, if you inscribe a dodecagon (12-sided polygon) and compute the ratio of the circumference to the radius, you will get a better approximation than if you do the same for a hexagon (6 sides). This makes sense if you draw it out. The polygons with the greater number of sides more closely resemble circles. It is important to remember Pi does not equal 3.14; instead, 3.14 is an approximation for Pi. Really Pi = 3.141592653... (it is an infinite decimal). Mathematicians began notating this ratio with the Greek letter Pi around 1706. Perhaps the letter Pi was chosen to represent "periphery" (Pi is the ratio of the circumference (periphery) to the diameter). I hope this helps. If not or if you have any other questions, please feel free to write back. Thanks! --Sydney, Dr. "Math Rocks" -Ken "Dr." Math |
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