Slope of a Line

PFA13, PFA14, and PFA7

In skiing, you will usually see these symbols

Easy Medium Hard

What is Slope?What is Slope?

Slope basically describes the steepness of a line. However, it uses

a numerical value not symbols.

Definitions of Slope

Slope is simply the change in the vertical distance over the change in the horizontal distance. The variable m is always used to represent slope.

12

12

xx

yy

x

y

run

risemslope

Means distance. It is the Greek letter Delta

12

12

xx

yym

The formula above is the one which we will use to find the slope of specific lines

In order to use that formula we need to know, or be able to find 2 points on the line

If a line is in the form Ax + By = C, we can use the following formula to find the slope:

B

Am

Positive or Negative SlopePositive or Negative Slope

If a line goes up from left to right, then the slope has to be positive

Conversely, if a line goes down from left to right, then the slope has to be negative

2x + 1y = -3( -1.5, 0 )

( 0 , -3)

Examples

1

2m

312 yx 0,5.1 and 3,0

05.1

)3(0

25.1

3

m

Either way. . .

We get m = -2

Horizontal lines have a slope of zero while vertical lines have no slope

HorizontalVertical

m = 0

m = no slope