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Glossary
Look up any term from this course. Each entry links back to the lesson that taught it.
| Term | Definition | Lesson |
|---|---|---|
| Complement (A′) | Every element of the universal set U that is not in A. | Complement and Difference |
| Composite function | fg() = f(()): apply first, then f to the result. | Composite Functions |
| Disjoint sets | Two sets with no elements in common, so their intersection is ∅. | Union and Intersection |
| Domain | The complete set of allowed input values for a function. | Domain and Range |
| Element (member) | One object belonging to a set. | What Is a Set? |
| Empty set | The set that contains no elements, written ∅ or { }. | Describing Sets |
| Finite set | A set with a countable, limited number of elements. | Describing Sets |
| Function | A relation where every input has exactly one output. | What Is a Function? |
| Infinite set | A set whose elements never end. | Describing Sets |
| Intersection (∩) | A ∩ B is every element in both A and B. | Union and Intersection |
| Inverse function | () reverses f, so (f()) = . | Inverse Functions |
| n(A) | The number of elements in set A. | Number of Elements |
| Range | The complete set of output values a function actually produces. | Domain and Range |
| Relation | A set of ordered pairs connecting inputs to outputs. | What Is a Relation? |
| Set | A well-defined collection of distinct objects, considered as a whole. | What Is a Set? |
| Set difference (A − B) | Every element in A that is not in B. | Complement and Difference |
| Subset | Set A is a subset of B (A ⊆ B) if every element of A is also in B. | Subsets |
| Three-set Venn diagram | A Venn diagram with three overlapping circles; fill centre first, then pairwise crescents, then only-regions, then none. | Three-Set Venn Diagrams |
| Union (∪) | A ∪ B is every element in A, in B, or in both. | Union and Intersection |
| Universal set | The set U containing every element under discussion in a problem. | Subsets |
| Venn diagram | A diagram using overlapping circles inside a rectangle to show how sets relate. | Venn Diagrams |
More lessons in Sets and Functions · Previous: Course Exam