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Research draft

function

vr.tr.function · XCT.REL

(mathematics) a mathematical relation such that each element of a given set (the domain of the function) is associated with an element of another set (the range of the function)

Thing Registry Cross-cutting context

Research draft, second pass

A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.

written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify

Researched by: Claude

Purpose and description

Let an agent handle functions by domain, codomain, rule and properties, separate from function in the sense of purpose or social event.

In mathematics, a relation that assigns to each element of a domain exactly one element of a codomain, such as polynomials, trigonometric functions and mappings between sets.

What it is for: Describing dependencies between quantities across mathematics, science and computing.

It can be evaluate it; plot it; analyse properties such as continuity; compose and invert functions.

Distinguishing features

Each input has exactly one output

Domain and codomain are part of the definition

Properties: injective, surjective, continuous

Programming functions are related but different

What it looks like

Formulas, graphs, tables or mappings.

How it is recognised

Notation f(x) or f: A -> B

Graphs passing the vertical line test

Polynomials are a family of functions

Related models

is a kind of - category

relation

includes - family

polynomial

is expanded as - representation

Taylor series

is confused with - another sense

function in programming

In practice

Families and kinds

polynomial functions

rational functions

exponential and logarithmic functions

trigonometric functions

functions of several variables

Standards and regulation

ISO 80000-2 notation

Failure modes and hazards

Ignoring domain restrictions

Confusing senses

Analytical facets

substance
abstract
origin
conceptual
agency
inert
mobility
not-applicable
scale
not-applicable
affordances
observable

Also called

polynomialmultinomialbiquadraticbiquadratic polynomialquartic polynomialhomogeneous polynomialmonic polynomialquadraticquadratic polynomialquanticmathematical functionsingle-valued functionmapmappingexpansioninverse functionmetric functionmetrictransformationreflectionrotationtranslationaffine transformationisometryoperatorlinear operatoridentityidentity elementidentity operatortrigonometric functioncircular functionsinesinarc sinearcsinearcsininverse sinecosinecosarc cosine

+34

Where this came from

oewn:2024 · CC BY 4.0

Drafted structure

Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.

Definition Which function.

Domain and rule define it.

Rule

Formula or mapping.

Rule

Rule.

  1. What rule defines the function? definition
  2. Is it well-defined? boundary

Domain

Inputs and outputs.

Domain

Domain and codomain.

  1. What are its domain and codomain? definition
  2. What is its range? measurement
Properties Behaviour.

Properties describe behaviour.

Mapping

Injective, surjective.

Mapping

Mapping properties.

  1. Is it injective, surjective or bijective? boundary
  2. Does it have an inverse? boundary

Analysis

Continuity.

Analysis

Analytic properties.

  1. Is it continuous or differentiable? boundary
  2. Where are its zeros and extrema? measurement
Representation Forms.

Functions have many forms.

Graph

Plot.

Graph

Graph.

  1. What does its graph look like? definition
  2. Which features should be shown? action

Series

Expansions.

Series

Series.

  1. Can it be written as a series? definition
  2. Where does it converge? boundary
Senses Disambiguation.

Function has many senses.

Other senses

Purpose, event.

Senses

Other senses.

  1. Is purpose, a social function or a programming function meant? boundary
  2. Which entry fits? action

Teaching

Explaining.

Teaching

Teaching.

  1. How can functions be explained clearly? action
  2. What misconceptions are common? boundary

What the second pass must settle

  • Should function families be separate entries?
  • How should programming functions be linked?
  • The registry aliases list polynomial types; should they link to a polynomial entry?