Date

1.1-Functions and Relations

Recall:

A relation is set of ordered pairs which include one value of the independent variable (X) and one value of

the dependent variable (A). Some examples of relations include lines (y = mx + b), circles (x2 + Y2 = r2)

and quadratics

(y = ax 2

+ bx + c).

A function is a relation in which every value of the

value of the dependent

The Vertical Line Test

variable produces a

variable.

One method of determining if a relation is a function is to use the " Vertical Line Test". To do this, place a

straight edge vertically over the page and move it across the graph. If the straight

edge ever crosses the graph at two points, the relation described by the graph is not a function.

Example 1: Determine if the following relations are functions

Function? YES o

Explain:

poess Ghe tesTRÄ(

d) -2 7

45

Function? YES

0160

Explain:

tbere is Than

Oode 9-value

b)

Function? E or NO

Explain:

e) 4

-1 5

o4

15

Function? €_oor NO

Explain:

c)

o4

1 7

10

313

Function? YE

Explain:

52

f) 21

3-6

16 9

x

or NO

Function? YES or NO

n For-eug±--