Question

explain how to determine whether two lines are parallel or perpendicular.
INCLUDE ALL CASES!
MEDALS REWARDED

Answer 1

Parallel lines: have the same slope
Perpendicular lines: for line with slope m, perpendicular line would have slope of -1/m

Answer 2

To determine if line are parallel, perpendicular, or neither, you must compare the slopes of the lines.
In the slope-intercept formula y = mx + b, the "m" is the slope.
RULES:
If the slopes are the SAME = parallel
If the slopes are OPPOSITE RECIPROCALS = perpendicular
If neither of these occur = neither parallel nor perpendicular
So just compare the slopes (m) in slope-intercept form (y = mx + b)

Answer 3

@mangorox @SolomonZelman thanks guys !! great help

Answer 4

YW

Answer 5

To see if two lines are Perpendicular. We will see the Angle they make where they meet, it should be 90.
And the product of their Slopes is -1
m1*m2 = -1
or
m1 = -1/m2

Perpendicular Test:


To see if two lines are Parallel we will see their Slopes, they should be same:
m1 = m2

Answer 6

thanks @Disco619 added a few extra words to the other help
greatly appreciated