What is pi?

π is equal to 3.14, and 3.14 is usually used to represent pi for approximate calculation. The decimal 3.141592653 is 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. ?

π is an irrational number, that is, it cannot be expressed as the ratio of two integers, which was proved by German scientist johann heinrich lambert in 1761. In 1882, Lin Deman proved that π is a transcendental number, that is, π cannot be the root of any integer coefficient polynomial.

The transcendence of pi denies the possibility of turning a circle into a square, because all rulers can only draw algebraic numbers, and the transcendence number is not algebraic.

Extended information:

The international pi day can be traced back to March 14th, 1988, when Larry Shaw, a physicist at the San Francisco Science Museum, organized museum staff and participants to make a circular motion around the museum monument for 3 1/7 times (22/7, one of the approximations of π) and eat fruit pies together. Later, the San Francisco Science Museum inherited this tradition and held celebrations on this day every year.

In p>29, the U.S. House of Representatives formally passed a non-binding resolution to designate March 14th as "pi day" every year. The resolution holds that since mathematics and natural science are interesting and indispensable parts of education.

And learning about π is a fascinating way to teach children geometry and attract them to study natural science and mathematics ... π is about 3.14, so March 14th is the most appropriate day to commemorate pi day.