Comparing Linear Functions 1

Comparing Linear Functions 1

How to format rate of change

•  $\frac{\text{change in output}}{\text{change in input}}$  

• Can keep as a fraction or divide the fraction to get a number

• Not written as a ratio

• Not written as a point (x, y)

Every linear function has:

• Rate of change

• Initial value (in proportional relationships, this is 0)

• y = mx + b

Phone Plan

Phone Plan

Compare to Phone Plan B:

A flat rate of $75 per month.

When do the two phone plans cost the same?

Faucet: filling a tub. What is the rate of gallons per minute?

Compare to faucet B:

faucet B:

 $y=\frac{5}{6}x$  

Which faucet fills a 50 gallon tub faster?

Compare savings rates

Linear functions can be written from...

• Graphs

• Tables

• Written situations

Poll

Opinion: With what presentation is it easiest to find the initial value?

• Equation

• Graph

• Table

• Word problem

Poll

Opinion: With what presentation is it easiest to find the rate of change?

• Equation

• Graph

• Table

• Word problem