Pi is the ratio of the circumference to the diameter of a circle, which is generally expressed by the Greek letter π, and it is a common mathematical constant in mathematics and physics. π is also equal to the ratio of the area of a circle to the square of the radius, which is the key value for accurately calculating the geometric shapes such as the circumference of a circle, the area of a circle, and the volume of a sphere. In analysis, π can be strictly defined as the smallest positive number x satisfying sinx=.
pi is written in the Greek letter π (pronounced [pa? ]) is a constant (approximately equal to 3.141592654) and represents the ratio of circumference length to diameter. It is an irrational number, that is, an infinite acyclic decimal. In daily life, 3.14 is usually used to represent pi for approximate calculation. The nine decimal places of 3.141592654 are enough for general calculation. Even if engineers or physicists want to make more precise calculations, at best, they only need to take values to hundreds of decimal places. ?
in p>1665, John Wallis, a British mathematician, published a mathematical monograph, in which he deduced a formula and found that pi was equal to the product of infinite fractions. In 215, scientists at the University of Rochester found the same formula of pi in the quantum mechanical calculation of hydrogen atomic energy level.
on March 14th, 219, Google announced that pi has now reached 31.4 trillion decimal places.
on August 17th, 221, American interesting science website reported that Swiss researchers used a supercomputer to calculate pi, a famous mathematical constant, to 62.8 trillion decimal places in 18 days, setting a record for the most accurate value of this constant so far.