The reciprocal or Multiplicative inverse of a real number is the number such that if multiplied by the resulting output is multiplicative identity.
More generally, let be a ring. Then the reciprocal of is such that , where 1 is the multiplicative identity of the ring.
The reciprocal of a fraction can be retrieved by swapping its numerator and denominator. Formally speaking, the reciprocal of a real number is equivalent to .