Algebra Concepts Section 8 1 Relations and Functions

Algebra Concepts Section 8. 1 Relations and Functions

Warmup • Name the ordered pairs!

• What are relatives?

• Relation-numbers that are paired together • Numbers are written as ordered pairs. • Each student provides the minutes they studied for a test and the grade they got. • One of the answers could be (60, 85)

• All the ordered pairs of the relation can be written as a set. {(60, 85), (20, 73), (40, 100), (45, 88), (0, 67), (15, 8 1)}

• Domain- set of first (x) coordinates • Range- set of second (y) coordinates {(60, 85), (20, 73), (40, 100), (45, 88), (0, 67), (15, 81)} Domain {60, 20, 45, 0, 15} Range {85, 73, 100, 88, 67, 81}

• Function- special relation where every x has a unique y • In a function, every x can be paired with only one y • It is okay for a y to paired with more than one x.

Is this a function? • This is not a function because 2 is paired with two different numbers.

Which one is a function?

Is the graph a function?

• When looking at a graph, you can use the Vertical Line Test to decide if the graph is a function.

• If a vertical line passes through more than one point, the graph is not a function.

• When one quantity depends on another, we say “One quantity (the range value) is a function of another quantity (the domain value). ”

Real life functions • Is the number of trips a mother makes to a dance studio a function of the number of dance classes her daughter goes to?

• Is the price you pay at the cash register a function of how many subs you buy?

• http: //www. youtube. com/watch? v=s. E 4 eq 0 cj. L Fk

Assignment #48 • Pg. 391 #1 -7, 14 -20, 29 -31