Set Notation And Interval Notation

Because negative infinity isn t a real number you use an open interval to represent it.

Set notation and interval notation. A x b is the inequality description. X a x b is the set builder notation. Interval notation is a method of writing down a set of numbers. Back miscellaneous mathematics mathematics contents index home.

The second interval is x 2. Represent inequalities using interval notation. Sets may be described in many ways. Another commonly used and arguably the most concise method for describing inequalities and solutions to inequalities is called interval notation.

For graphing on a number line see. The interval 3 5 is written in set notation as read as the set of all real numbers x such that. With this convention sets are built with parentheses or brackets each having a distinct meaning the solutions to latex x geq 4 latex are represented as latex left 4 infty right latex. The function must work for all values we give it so it is up to us to make sure we get the domain correct.

Methods of describing sets. Suppose that a and b are real numbers such that a b. Beyond that set notation uses descriptions. C denotes the set of all complex numbers.

X in mathbb r x 5 or 10 x 20 or x 100 finally note that if the. This set is all numbers between 2 and positive infinity. Interval notation calculator inequality calculator absolute value interval notation compound inequality set builder notation calculator. For example if your set is composed by all the numbers smaller than 5 or between 10 and 20 or greater than 100 you write the following union of intervals.

So in interval notation you write this part of the set as. Is the empty set the set which has no elements. In its simplest form the domain is the set of all the values that go into a function. Set builder notation is very useful for defining domains.

R denotes the set of all real numbers consisting of all rational numbers and irrational numbers such as. Notation plays an important role in mathematics. Then the open interval a b represents the set of all real numbers between a and b except a and b. This interval includes all numbers between negative infinity and 4.

This video introduces how to read and write interval and set notation. By roster by set builder notation by interval notation by graphing on a number line and or by venn diagrams. Usually this is used to describe a certain span or group of spans of numbers along a axis such as an x axis. The first interval is x 4.

Elements in a set do not repeat.