The ignition formula is also called Wallis formula, which is about the infinite product of pi, but there is only multiplication and division in Wallis formula, and even the root sign is not needed, so the form is very simple. Although Wallis formula has no direct influence on the approximate calculation of π, it plays an important role in the derivation of Stirling formula.
Wallis formula is a formula about the infinite product of pi, and the content of the formula is as follows:
Formulas, in mathematics, physics, chemistry, biology and other natural sciences, use mathematical symbols to express the relationship between several quantities. It is universal and applicable to all similar problems. In mathematical logic, a formula is a formal grammatical object to express a proposition, but the proposition may depend on the free variable value of the formula.
The precise definition of a formula depends on the specific formal logic involved, but there is a very typical definition (for first-order logic): the formula is defined relative to a specific language; That is, a set of constant symbols, function symbols and relational symbols, in which each function and relational symbol has an arity to indicate the number of parameters it accepts.