Slope•is a number, which describes the steepness on the line

•usually a fraction

•that tells how a line slants

•comes in 4 “flavors”:

positive, negative, zero, no slope or undefined

•Finding slope or slant of a line ALWAYS read from left to right

Slope

Lines that slant uphillhave a POSITIVE slope.Riding the chair lift

Lines that slant downhillhave a NEGATIVE slope. Skiing down hill

Slope

Horizontal lines havea slope of zero (0). Cross Country skiing

Vertical lines have no slope (undefined). Skiing off a cliff

SlopeSlope is abbreviated with a lower case letter m.

change in y ym

change in x x

Run

Risem

Slopechange in y y

mchange in x x

NOTE: Line slants downhill, so the slopeis negative.4y

6x

2

3

ym

x

RUN

Rise

6

4

Run

Risem

Slopechange in y y

mchange in x x

NOTE: Line slants uphill, so the slopeis positive.

2

5

ym

x

4y

10x 10

4

Run

Risem

Slope Formula1 1 1: ( , )P x y

1 1 1: ( , )P x y

2 2 2: ( , )P x y

2 2 2: ( , )P x y

2 1y y y

2 1x x x 2 1

2 1

y ym

x x

ym

x