R1.1 REAL NUMBERS ORDER AND ABSOLUTE VALUE

Set – A collection of objects Sub-set – Some of the items in the set

RATIONAL NUMBERS Numbers that can be written as a quotient of two integers No zeros allowed in the denominator Numbers that can be written as decimals that either terminate or repeat

INTEGERS {… -3, -2, -1, 0, 1, 2, 3 …}

NATURAL NUMBERS {1, 2, 3, 4 …} Numbers that are used for counting

IRRATIONAL NUMBERS Numbers that cannot be written as a quotient of two integers Decimals that do not terminate and do not repeat

PRACTICE

ABSOLUTE VALUE

INEQUALITIES Inequality tells you about the relative size of two values. Sentences containing, ≤, ≥, or ≠

Ex.: x < 0 represents the set of all numbers less than zero Inequality Notation: Number Line: Interval Notation:

Ex.: x ≥ 5.6 represents the set of all numbers greater than or equal to 5.6. Inequality Notation: Number Line: Interval Notation:

PRACTICE Give a verbal description and the interval notation of the subset of real numbers that is represented by the inequality, and sketch the subset on the real number line. 1.x < ≤ x ≤ 5