Slide 2:
Line Relationships (Perpendicular Lines)
Here are two lines that are perpendicular to one another. Let’s try to see what the relationship between the slopes is. :
Here are two lines that are perpendicular to one another. Let’s try to see what the relationship between the slopes is. Line 1:
Line 2: Remember that slope-intercept formula- y= mx + b What would we get if we multiply the two slopes together?
Slide 4:
The product of the slopes of two perpendicular lines is -1.
Now lets see what the graph would look like. :
Now lets see what the graph would look like. y= mx + b
Remember m is the slope and b is the y intercept. y = - 4/3 + 3First- plot your point at 0, 3 since the y intercept is 3.Then find your next point using slope, rise/run.
Go down 4 and over to the right 3. There is your next point.
Now do the same with the next
equation. See, the lines are perpendicular - they cross at a 90 degree angle.
Slide 6:
The product of the slopes of two perpendicular lines is -1.