Reciprocal is a mathematical term, which means that the product of a number x multiplied by it is 1, which means that all numbers except 0 have reciprocal. The numerator and denominator are inverted, the number whose product is 1 is reciprocal, and 0 has no reciprocal.

Countdown with scores. First, turn the fraction into a false fraction, then switch the numerator and denominator, which is the reciprocal of the number. In advanced mathematics, complex numbers also have reciprocal, for example, the reciprocal of I is-I.

In number theory,

There is also the concept of reciprocal number theory. If the product of two numbers A and B is 1 relative to the module M, then we call them the number theory reciprocal of the module M. 3 is the reciprocal of 2, is it about 5? The reciprocal of number theory is very important in China's remainder theorem. The alternate division provides a method to calculate the reciprocal of number theory.