Module 1 Topic 3: Proportionality

Variable

A letter or symbol that is used to represent a number

Direct Variation

A situation where the ratio between the y-value and the it corresponding x-value is constant (the same) for every point

Proportion

An equation that states that two ratios are equal

Constant of Proportionality (COP)

In a proportional relationship, the ratio of all the y-values to the corresponding x-values is constant. x/y = k.

Table

Information (such as numbers and descriptions) arranged in rows and columns.

Origin

Is a point on a graph with the ordered pair (0,0)

Proportional Relationship

The ratio of the inputs to the output is constant (equal to one another). Represented by a graph that goes through the origin.

Input

The variable "x" represents the input and can be manipulated. It is what gets plugged in to an equation

Output

The variable "y" represents the output and depends on the "x" value. It is the answer you get when you solve an equation.

Graph

a line or curve drawn on a number line or coordinate plane by joining the points represented by certain ordered pairs