3 o'clock14159265358979323846644, etc. , is a π number, also called pi, is an infinite cyclic number, endless. Pi is the ratio of the circumference to the diameter of a circle, which is generally expressed by the Greek letter π and is a universal mathematical constant in mathematics and physics. Pi is the key value to accurately calculate the geometric shapes such as circumference, circle area and sphere volume.

The importance of pi

Pi is the ratio of the circumference to the diameter of a circle, which is generally expressed by the Greek letter π and 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 its radius. Accurate calculation of geometric shapes such as circle perimeter, circle area and sphere volume is the key value. In the analysis, π can be strictly defined as the smallest positive real number x that satisfies 0, such as sinx.

Pi is expressed by the Greek letter π pronounced pài, which is a constant equal to about 3 points 14 1592654, representing the ratio of circumference to diameter. It is an irrational number, that is, an infinite cycle decimal. In daily life, we usually use 3 points 14 to express pi for approximate calculation. The decimal point of 3: 14 1592654 is enough for general calculation.

John wallis, a British mathematician, published a mathematical monograph in which he deduced a formula and found that pi is equal to the product of infinite fractions. 20 15 scientists at the university of rochester found a formula with the same pi in the quantum mechanical calculation of hydrogen atomic energy level. On August 8, 20021,18, pi was calculated to 6.28 trillion decimal places, setting a record for the most accurate value of this constant so far.