Relations vs Functions: Difference and Comparison

Relations and functions are inextricably linked. To be capable of discriminating between relations and functions, one should have a thorough understanding of the concepts.

Throughout this article, we will differentiate between relations & functions. A function could have the same range mapping, just like a relation, so a collection of inputs corresponds to precisely one yield.

Key Takeaways

1. A relation is a set of ordered pairs showing the relationship between two sets, while a function is a relation where each input has a unique output.
2. A relation can have multiple outputs for a single input, while a function can only have one output for a single input.
3. The vertical line test can be used to determine whether a relation is a function or not.

Relations vs Functions

A relation is a set of ordered pairs, while a function is a special kind of relation in which each input (or “domain”) value corresponds to exactly one output (or “range”) value. A function is a special kind of relationship where each input value corresponds to exactly one output value.

In Maths, a relation is defined as connectivity between components of two or more sets, and that shouldn’t be empty. The Cartesian union of subsets yields a relation R.

Assume we possess 2 sets; if there is a relationship between both the items followed by a non-sets, therefore the only relation is constructed between both the components.

A function f: X→Y inside the structural method is a binary relation among X and Y that relates one Y component to every X component.

That also is, f is determined as just a set G of ordered pairs (x, y) containing x X, y Y, and each component of X being the initial constituent of precisely 1 ordered pair within G.

Comparison Table

Parameters of Comparison	Relations	Functions
Meaning	A Relation can be described as a connection between the two sets of values. Alternatively, it is just a subset of both the Cartesian product.	A function can be expressed as a relation with the only a single outcome for each input.
Denoted By	The letter “R” is commonly used to signify a relation.	A function is commonly symbolized by the letters “F” or “f.”
Correlation	Each relation, we could conclude, isn’t really a function.	In Mathematical terms, we can claim that each and every function is also a relation.
Types	The different types of relations include Empty Relation, Universal Relation, Identity Relation, Inverse Relation, Reflexive Relation, Symmetric Relation, Transitive Relation, and Equivalence Relation.	The different types of functions include Identity Function, Constant Function, Polynomial Function, and Rational Function.
Linked to	Theoretical notions are formed through the usage of relations.	A function is associated with a single element.

What are Relations?

A relation is a conceptual mathematical model that establishes some relationship between the components of 2 sets. It’s a much more generalized version of the much more frequently recognized concept of mathematical formalism but with fewer constraints.

A relation spanning sets X and Y is a collection of ordered pairs (x, y) made up of components x in X and y in Y.

It embodies the standard relation methodology: component x is connected to a component y if and only when the pair (x, y) conforms to the internal node-set, specifying the binary relation.

Any binary relation is by far the most researched n = 2 special instance of an n-ary relation across sets X1,…, Xn, which would be a subset of something like the Cartesian products X1… Xn.

The sets of all pairings about which constituents x=y is a simple analogy of a binary relation spanning set X among all real numbers R as well as set Y including all real numbers R.

What are Functions?

Any function from such a set X to another set Y is an allocation of a Y component to each component of X. This set X is referred to as the function’s domain, while the set Y is referred to as the function’s codomain.

Functions have been the idealization of how a variable element relies on some other value. For instance, the location of a star seems to be a function of time.

Traditionally, the framework was proposed well with infinitesimal calculus somewhere at the end of the 1600s, as well as the functions investigated were distinguishable till the late nineteenth century. 

The idea of a function became codified in concepts of set theory now at the end of the nineteenth century, which substantially expanded the method’s realms of applicability.

The graphs of any function are the collection of all pairings (x, f (x)) that consistently express a function.

Whenever the domain and the codomain represent real number sets, every combination can be conceived as one of the Cartesian coordinates systems of a point within planes.

Main Differences Between Relations and Functions

1. A Relation can be described as a connection between the two sets of values. Alternatively, it is just a subset of both the Cartesian product. On the other hand, a function can be expressed as a relation with only a single outcome for each input.
2. The letter “R” is commonly used to signify a relation. Whereas a function is commonly symbolized by the letters “F” or “f.”
3. Each relation, we could conclude, isn’t really a function. On the other hand, in Mathematical terms, we can claim that each and every function is also a relation.
4. The different types of relations include Empty Relation, Universal Relation, Identity Relation, Inverse Relation, Reflexive Relation, Symmetric Relation, Transitive Relation, and Equivalence Relation. In contrast, different types of functions include Identity Function, Constant Function, Polynomial Function, and Rational Function.
5. Theoretical notions are formed through the usage of relations. Whereas a function is associated with a single element.

References

1. https://aapt.scitation.org/doi/abs/10.1119/1.15378?journalCode=ajp
2. https://www.cambridge.org/core/journals/journal-of-symbolic-logic/article/abs/gelfondmichael-and-lifschitzvladimir-the-stable-model-semantics-for-logic-programming-logic-programming-proceedings-of-the-fifth-international-conference-and-symposium-volume-2-edited-by-kowalskirobert-a-and-bowenkenneth-a-series-in-logic-programming-the-mit-press-cambridge-mass-and-london-1988-pp-10701080-finekit-the-justification-of-negation-as-failure-logic-methodology-and-philosophy-of-science-viii-proceedings-of-the-eighth-international-congress-of-logic-methodology-and-philosophy-of-science-moscow-1987-edited-by-fenstadjens-erik-frolovivan-t-and-hilpinenristo-studies-in-logic-and-the-foundations-of-mathematics-vol-126-north-holland-amsterdam-etc-1989-pp-263301/52AF3E8E306327B3CD6C5D13CF7D897C

Last Updated : 11 June, 2023