If the lines are in the form y = mx + c, the m values multiplied together should equal -1.
Otherwise, the dot product of the two slope vectors should equal 0.
Actually it IS. perpendicular lines have opposite reciprocal slopes and parallel lines have the same slope.
Slopes of line perpendicular to the x-axis are undefined.
2
Parallel lines have the same slope.
-1
There is no relationship between the slopes of parallel or perpendicular lines and their y-intercepts.
If the slopes are m1 and m2 then m1*m2 = -1 or m2 = -1/m1.
If the lines are perpendicular, their slopes are negative reciprocals.If the lines are perpendicular, their slopes are negative reciprocals.If the lines are perpendicular, their slopes are negative reciprocals.If the lines are perpendicular, their slopes are negative reciprocals.
The relationship between perpendicular lines lies in there slopes. The slope of one line is the opposite reciprocal of the other. Written mathematically, the lines y=m*x +b and y =(-1/m)*x +c are perpendicular lines (note the y-intercepts do not need to be equal or even related to each other).
I believe they have Negative Slopes as stated by my Geometry Book. "Perpendicular Lines Have Slopes Which Are Negative ___"
Actually it IS. perpendicular lines have opposite reciprocal slopes and parallel lines have the same slope.
Negative reciprocal slopes always represent perpendicular lines.
Take any two lines and look at their slopes. -- If the slopes are equal, then the lines are parallel. -- If the product of the slopes is -1, then the lines are perpendicular.
Slopes of line perpendicular to the x-axis are undefined.
To determine if a line with slope ( m ) is perpendicular to another line, you need to check the relationship between their slopes. Two lines are perpendicular if the product of their slopes is (-1). Therefore, if you have the slope of one line, you can find the slope of a perpendicular line by taking the negative reciprocal of that slope. If ( m ) is equal to this negative reciprocal, then it is a perpendicular line.
negative reciprocal slopes ---> the lines are perpendicular equal slopes ---> the lines are parallel
When the perpendicular lines are horizontal and vertical.