Identify linear functions from graphs and equations

Distinguish linear functions by constant rate of change and straight-line graphs.

Lesson 4

Concept

Linear functions have the form y = mx + b and graph as straight lines with constant slope.

Decide whether y = 4x - 7 and y = x² + 1 are linear, then justify.

Which equation is linear?

y = 3x + 5

y = x² - 2

y = 1/x

y = √x

A graph with constant slope is:

Linear

Quadratic

Exponential

Random

These steps are out of order — can you fix them?

1.Check graph shape

2.Conclude linear/nonlinear

3.Check if slope is constant

4.Verify equation is y = mx + b

Name one sign that a relation is not linear.