1. Lines in the Plane and Slope
Sec. 2.1
Lines in the Plane and Slope

2. The Slope of a Line
The slope of a nonvertical line represents the number of units the line rises or falls vertically for each unit of horizontal change from left to right.

3. The Slope of a Line Definition of the Slope of a Line
The slope m of the nonvertical line through is
where
Why

4. Slope intercept Form Slope intercept form of the equation of a line is
y = mx + b
slope
y intercept
x & y are the coordinates for all points on that line

5. x = a vertical line
slope is undefined
y = a Horizontal line
0 slope

6. Sketch the graph
y =⅔x – 6
y = -½ x
y = 4
x = -2
5x – 2y = 6

7. Real Life Slope is either a ratio or rate.
Ratio – x & y have the same units so the slope ends up unitless (no units)
Rate – x & y have different units so the slope has units called rate of change

8. Ex. 2
Recommended slope of a wheelchair ramp is 1/12. A ramp rises 22 in over a horizontal length of 24 ft. Is the ramp steeper than recommended?