👉 Joining math, also known as set theory or union in mathematical notation, is a fundamental operation that combines elements from multiple sets into a single set. Given two sets A and B, the union of A and B, denoted as A ∪ B, is a set containing all elements that are in A, in B, or in both. For example, if A = {1, 2, 3} and B = {3, 4, 5}, then A ∪ B = {1, 2, 3, 4, 5}. This operation can be extended to any number of sets, where the union of multiple sets retains all unique elements across all sets. The principle of inclusion-exclusion is often used when dealing with more complex unions, ensuring that each element is counted exactly once. This concept is crucial in various areas of mathematics, including algebra, analysis, and combinatorics.
