Unit 3 - Proportional Relationships (Pre-Algebra)

Positive

Negative

Zero

Undefined

 $\left(x_1,\ y_1\right)\ and\ \left(x_2,\ y_2\right)$  

 $slope=m=\frac{y_2-y_1\text{y}}{x_2-x_1}$  

Equations of proportional relationships are in the form:   $y=mx$ , where represents the slope (unit rate, constant of proportionality, rate of change). 

Graphs of proportional relationships begin at the origin and are straight diagonal lines. 

A table represents a proportional relationship if all values of  $\frac{y}{x}$  are the same. 

A relation is a function if there are NO REPEATS in the DOMAIN.

The DOMAIN is also referred to as the INPUT or the X-VALUES.

The RANGE is also referred to as the OUTPUT or the Y-VALUES.

Functions can be represented as a set of ordered pairs, in tables, in graphs, in equations, and in mapping diagrams.