  ## Math Symbols The Most Valuable and Important Symbols For Set Notation In Use: "Intersection of Sets" Math Symbols: . . . why math symbols are used . . .

Symbols are a concise way of giving lengthy instructions related to numbers and logic.

Symbols are a communication tool. Symbols are used to eliminate the need to write long, plain language instructions to describe calculations and other processes.

For example, a single symbol stands for the entire process for addition. The familiar plus sign eliminates the need for a long written explanation of what addition means and how to accomplish it.

The same symbols are used worldwide . . .

The symbols used in mathematics are universal.

The same math symbols are used throughout the civilized world. In most cases each symbol gives the same clear, precise meaning to every reader, regardless of the language they speak.

The most valuable, most frequently used Symbols in mathematics . . .

The most important, most frequently used Symbols for Set Notation are listed below. Go To
"All Math Symbols"   "Top of Page" Math Symbol for the "Intersection of Sets" -

D A equals a new set which includes only those common elements which appear in both Set "D" AND Set "A".

This is similar to the intersection of two streets. The area of overlap, where the two streets cross one another, is the intersection.

Example 1: , Set A:   A = { a, b, c, d }

Set D:   D = { e, f }

. . . The Intersection of Set "D" and Set "A" produces an EMPTY SET (a NULL Set). Set "A" and Set "D" have no elements in common with one another.

D A = {}

D A = Note: Set "A" and Set "D" are called Disjoint Sets because they have no common elements.

Example 2: , Set B:    B = { 1, 3, 9, 11 , 13,                          14 }

Set E:   E = {1, 3, 9, 11}

. . . Both Set "E" and Set "B" contain some of the same elements: 1, 3, 9, 11. These common elements are the intersection of the two Sets.

E B = {1, 3, 9, 11}

Example 3: , Set C:    C = {dog, horse, bird,                          rabbit, cat }

Set F:   F = {cat, rabbit}

. . . Both Set "F" and Set "C" list the following elements in a different order: rabbit, cat.

F C = {rabbit, cat}

Note: the elements within a SET can be listed in any order.