Reciprocal may refer to:

In mathematics

* Multiplicative inverse, in mathematics, the number 1/''x'', which multiplied by ''x'' gives the product 1, also known as a ''reciprocal'' * Reciprocal polynomial, a polynomial obtained from another polynomial by reversing its coefficients * Reciprocal rule, a technique in calculus for calculating derivatives of reciprocal functions * Reciprocal spiral, a plane curve * Reciprocal averaging, a statistical technique for aggregating categorical data

In science and technology

* Reciprocal aircraft heading, 180 degrees (the opposite direction) from a stated heading * Reciprocal lattice, a basis for the dual space of covectors, in crystallography *

Reciprocal length Reciprocal length or inverse length is a quantity or measurement used in several branches of science and mathematics. As the reciprocal of length, common units used for this measurement include the reciprocal metre or inverse metre (symbol: m− ...

, a measurement used in science * Reciprocating engine or piston engine * Reciprocating oscillation in physical wave theory

Life sciences and medicine

* Hybrid (biology), in genetics, the result of a reciprocal pair of crossings, forming ''reciprocal hybrids'' * Reciprocal altruism, a form of symbiotic relationship in evolutionary biology * Reciprocal cross, a breeding experiment in genetics * Sherrington's law of reciprocal innervation in the theory of muscle activation

Social sciences

Reciprocal determinism Reciprocal determinism is the theory set forth by psychologist Albert Bandura which states that a person's behavior both influences and is influenced by personal factors and the social environment. Bandura accepts the possibility that an individua ...

, a theory in psychology

Linguistics

* Reciprocal construction, a construction in which agent and patient are in a mutual relationship

In reciprocal relationships