2.3 Venn Diagrams and Set Operations Flashcards
Venn diagram
A useful technique for illustrating set relationships. The rectangle represents the universal set, and the circle represents the subsets.
Disjoint
Mutually exclusive. Two separate circles (subsets) in the box (universal set). Can’t happen at the same time.
Subsets
Circle (subset) inside another circle (subset).
Equal sets
Two sets that have the same members. One circle (subset) in box (universal set).
Overlapping sets
Traditional venn diagram in box.
Complement 𝐴′ (also A^C, 𝐴~)
The set of all elements in the universal set that are not in another set. (Ex: U = {a, b, c, d, e} A = {a, c, e} thus A’ = {b, d}) In a venn diagram, complements are represented outside of the circles (subset).
Intersection A ∩ 𝐵
The set containing all the elements common to both set A and set B.
∩ meaning “and” or “intersects”
Union ∪
The set containing all the elements that are members of set A or set B (both sets)
∪ meaning “or” or “union”
n(A∪B) = n(A) + n(B) - n(A∩B)
General addition rule
Difference of two sets (A - B)
The set of elements that belong to set A but not set B. Subtract the intersection.
Cartesian Product (A × B)
The set of all possible ordered pairs of the form. Multiplying.