Find the slope of a graph

Measure slope from a line graph and connect it to steepness and direction.

Lesson 1

Concept

Slope quantifies steepness: positive slopes rise, negative slopes fall, zero slope is horizontal, undefined slope is vertical.

Find the slope of a line through (2, -1) and (6, 7).

A vertical line has slope:

Undefined

-1

If slope is -3, the line moves:

Up 3 for right 1

Down 3 for right 1

Up 1 for right 3

Flat

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

1.Compute slope

2.Determine sign

3.Interpret steepness

4.Connect to context

Why can two lines with positive slope look different?