Some people claim that pi is wrong, which probably stems from a paper published by American mathematician Bob Paley in Mathematical Information 200 1. The topic of the paper is π wrong! Later, it was welcomed by some mathematicians, because the formula about circle used radius more.
For example, the radius is used in the area formula of a circle, and the diameter is only used in the perimeter formula of a circle, resulting in the angle of a circle being 2π and the semicircle being π, which makes some mathematicians quite unhappy, so they put forward that pi should be the ratio of perimeter to radius, and this pi is recorded as "set" and τ=2π, so many formulas will be more beautiful to write.
For example, perimeter C=τr, area S=τr, Dirac constant =h/τ, trigonometric formula sin(a)=sin(a+τ), Stirling formula n! (τ n) (n/e), Euler formula e= 1 and so on.
These people think that we should use τ-the ratio of the circumference to the radius of the circle, which is about 6.28. According to this definition, τ=2π. Using τ as pi can only change the form slightly in some formulas, and the convenience is very limited, so π does not need to be replaced.
But this doesn't mean that π is really wrong, but the expression is different, so there is no need to delve into it. You should continue to use π, and you can use τ if you want. Anyway, the relationship between the two is only twice.
In addition, 3. 14 was not initiated by Zu Chongzhi. Mathematicians in China first got this value from Liu Hui, who was 200 years earlier than Zu Chongzhi. But China didn't get the value of 3. 14 at the earliest. The ancient Greeks knew that pi was 3. 14 16 400 years earlier than China. Zu Chongzhi's contribution to pi lies in his accuracy of π to seven decimal places, which has been ahead of the world for the next 800 years.
Zu Chongzhi s main contribution to pi;
First of all, he used Liu Hui's secant circle method to calculate the exact values of pi between 3. 14 15926 and 3. 14 15927, which is a fairly good approximation.
Secondly, he gave a good result of 355/ 1 13 (called density) as an approximation of pi. The approximate accuracy reaches six decimal places.