In China's ancient book "Parallel Calculation of Classics in Weeks" (about 2nd century BC), it is recorded that "Dao is one and Wednesday", which means π=3. Did Zhang Heng get π in Han Dynasty? Divided by 16 is about five eighths, that is, π is about equal to the root number ten (about 3. 162). This value is not accurate, but it is easy to understand. ?
China mathematician Liu Hui uses secant method to calculate pi. He first connected a regular hexagon in a circle, and then divided it step by step until a regular hexagon was connected in the circle 192. Liu Hui gave an approximate value of pi =3. 14 1024. After getting pi = 3. 14, Liu Hui continued to tangent to 1536 and calculated the area of 3072. The satisfactory pi of 3927 divided by 1250 is about 3.
Mathematician Zu Chongzhi further got the result accurate to 7 decimal places, and gave the shortage approximation of 3. 14 15926 and the surplus approximation of 3. 14 15927. Density is a good fractional approximation, and the ratio of 355 divided by 16604 can be obtained.
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20 1 1 year, the International Mathematical Association officially announced that March 14 every year would be designated as the International Mathematics Festival, which originated from the pi of Zu Chongzhi, an ancient mathematician in China. ?
1965, the British mathematician john wallis published a mathematical monograph, in which he derived 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.
2065438+On March 4th, 2009, Google announced that Pi has now reached 3 1.4 trillion digits after the decimal point.
Baidu encyclopedia -pi