Find the reciprocal (multiplicative inverse) of a number or fraction.
The reciprocal of a number x is 1/x. For a fraction a/b, the reciprocal is b/a. Multiplying any non-zero number by its reciprocal always gives 1. Zero has no reciprocal.
Reciprocal
Reciprocal of a/b = b/a; Reciprocal of x = 1/x
Because 1/0 is undefined — there is no number that multiplied by 0 gives 1.
The reciprocal is specifically the multiplicative inverse (1/x). The additive inverse is −x. These are different operations.