background preloader

Pi

Facebook Twitter

Le number PI: doc word.

Il faut qu'on complete surtout les activités et aussi son utilité dans la vie de tous les jours! – milnertori

Idée de plan. Autre.

And easy way to remember the first few digits is this: "May I have a large container of butter today" 3 1 4 1 5 9 2 6 5 – milnertori

PI. Pi is a name given to the ratio of the circumference of a circle to the diameter.

PI

That means, for any circle, you can divide the circumference (the distance around the circle) by the diameter and always get exactly the same number. It doesn't matter how big or small the circle is, Pi remains the same. Pi is often written using the symbol and is pronounced "pie", just like the dessert. Le nombre Pi. Qu'est-ce que le nombre p ?

Le nombre Pi

"p = 3,14" comme on dit ... Idées d'activités. Pi Day: Pi Activities & Links. Materials large sheet of drawing paper or cardboard meterstick pen toothpicks (30 or more) calculator To Do and Notice Draw a series of parallel lines on the paper or cardboard, as many as will fit, making sure that the distance between each line is exactly equal to the length of your toothpicks.

Pi Day: Pi Activities & Links

Now, one by one, randomly toss toothpicks onto the lined paper. Keep tossing until you’re out of toothpicks—or tired of tossing. It’s time to count. First, remove any toothpicks that missed the paper or poke out beyond the paper’s edge. The Pi-Search Page. Origine/historique. Pi Day: History of Pi. Pi has been known for almost 4000 years—but even if we calculated the number of seconds in those 4000 years and calculated pi to that number of places, we would still only be approximating its actual value.

Pi Day: History of Pi

Here’s a brief history of finding pi: The ancient Babylonians calculated the area of a circle by taking 3 times the square of its radius, which gave a value of pi = 3. One Babylonian tablet (ca. 1900–1680 BC) indicates a value of 3.125 for pi, which is a closer approximation. The Rhind Papyrus (ca.1650 BC) gives us insight into the mathematics of ancient Egypt. The Egyptians calculated the area of a circle by a formula that gave the approximate value of 3.1605 for pi. The first calculation of pi was done by Archimedes of Syracuse (287–212 BC), one of the greatest mathematicians of the ancient world. A similar approach was used by Zu Chongzhi (429–501), a brilliant Chinese mathematician and astronomer. Mathematicians began using the Greek letter π in the 1700s. History.

Why use the letter Pi and not alpha or Beta? Well, it's Pi as in "Perimeter "- the letter Pi in Greek is like the letter P in english. – milnertori
Je pense qua ca suffit pour l'historique – milnertori
The greek letter for Pi was first used by mathematician William Jones, in 1706. – milnertori

What is pi, and how did it originate? Steven Bogart, a mathematics instructor at Georgia Perimeter College, provides the following explanation: Succinctly, pi--which is written as the Greek letter for p, or --is the ratio of the circumference of any circle to the diameter of that circle.

What is pi, and how did it originate?

Regardless of the circle's size, this ratio will always equal pi. In decimal form, the value of pi is approximately 3.14. But pi is an irrational number, meaning that its decimal form neither ends (like 1/4 = 0.25) nor becomes repetitive (like 1/6 = 0.166666...). Was first used for this purpose by William Jones in 1706, probably as an abbreviation of periphery, and became standard mathematical notation roughly 30 years later. Try a brief experiment: Using a compass, draw a circle. Otherwise said, if you cut several pieces of string equal in length to the diameter, you will need a little more than three of them to cover the circumference of the circle. Calcul de Pi. Calcul de Pi selon Archimède. Archimède a inventé, vers 250 avant J-C, une méthode originale pour le calcul de la longueur d'un cercle.

Calcul de Pi selon Archimède

Il encadre en effet cette valeur par le périmètre d'un polygone régulier inscrit dans ce cercle, et par le périmètre d'un polygone régulier exinscrit : Archimedes_pi. MC2004-Pi-Archimede. Les décimales de pi. Vous avez sans doute entendu parler du nombre \pi qui intervient dans les formules que l’on apprenait à l’école élémentaire : 2\,\pi\,r pour le périmètre du cercle de rayon r et \pi\,r^2 pour l’aire délimitée par ce cercle (actuellement cela s’apprend en CM2 pour le périmètre et en 6ième pour l’aire).

Les décimales de pi

Je me souviens aussi des valeurs approchées (3,14 ou 3,1416 ou 22/7) de ce nombre que j’ai apprises au CM1 au cours d’une leçon qui m’a marqué pour la vie. Notre instituteur nous apprit ainsi que le nombre \pi permet de calculer le périmètre de tous les cercles, quel que soit leur rayon, et aussi l’aire des disques qu’ils délimitent. Le plus impressionnant pour moi fut d’apprendre que ce nombre a une infinité de décimales et que personne ne peut en donner la liste ni la décrire. Le nombre 1/3 a une infinité de décimales et ce sont toutes des 3 ; la suite des décimales du nombre{2\over 7}=0,2857\,142857\,142857\dots Naissance des mathématiques européennes : la Grèce Vers 600 av. Qu'est-ce que c'est ? A quoi ça sert ?

What is it used for? Pi is used in many things. It is especially usefull for pilots, and people who work with planes. With pi they can calculate how much fuel they will use when flying in an arched mouvement. When planes fly long distances they are flying – milnertori

How Pi Works" Pi is an extremely interesting number that is important to all sorts of mathematical calculations.

How Pi Works"

Anytime you find yourself working with circles, arcs, pendulums (which swing through an arc), etc. you find pi popping up. We have run into pi when looking at gears, spherical helium balloons and pendulum clocks. But you also find it in many unexpected places for reasons that seem to have nothing at all to do with circles. MathSteps: Grade 6: Pi: What Is It? There are many fascinating numbers in mathematics.

MathSteps: Grade 6: Pi: What Is It?

One of the most interesting number relationships that students can discover in geometry is that the ratio of the circumference of a circle (the distance around a circle) to the diameter of a circle (the length of a line across a circle that passes through its center) is approximately equal to 3.14 or . This ratio is true for all circles. What is Pi ?

Pas "it permits" It allows us to calculate... – milnertori

Pi. Pi.