Algebra 1 : Equations of Lines
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Example Questions
Example Question #1 : How To Find The Slope Of Perpendicular Lines
Find the slope of the line that is perpendicular to the line that contains (1, 9) and (3, 4).
–5/2
4/3
5/2
2/5
–2/5
2/5
The slope of the line that contains the points (1, 9) and (3, 4) is 
The negative reciprocal is 
Example Question #1 : How To Find The Slope Of Perpendicular Lines
If the slope of a line is equal to 
Slope of lines that are perpendicular to each other are the negative reciprocal.
Example Question #1 : How To Find The Slope Of Perpendicular Lines
Two lines are perpendicular to each other. One of the lines is depicted by the equation 
Perpendicular lines have slopes that are negative reciprocals of one another. Since the original line has a slope of 
Example Question #1 : How To Find The Slope Of Perpendicular Lines
Two lines are perpendicular to each other. One of the lines' equations is 
What is the slope of the other line?
Perpendicular lines have slopes that are negative reciprocals of one another. The given line's slope is 5, which means that the slope of the other line must be its negative reciprocal. The negative reciprocal of 5 is 
Example Question #1 : How To Find The Slope Of Perpendicular Lines
What is the slope of a line that is perpendicular to
Perpendicular lines have slopes that are negative inverses of one another. The slope of the given line is 
Example Question #2 : How To Find The Slope Of Perpendicular Lines
What is the slope of a line that is perpendicular to
The slopes of perpendicular lines are negative inverses of each other. The slope of the given line is 
Example Question #1 : How To Find The Slope Of Perpendicular Lines
Find the slope of a line that's perpendicular to the following linear equation:
none of these
We are given
To find the slope that's perpendicular, we perform the following steps
- First, take the slope from our original equation. In our equation, the slope is
- Take the reciprocal of that slope. The reciprocal is
.
- Finally, change the sign so that we end up with
. This is the number that represents the slope of the perpendicular line.
Another way to think of this problem is that the general formula for the slope that's perpendicular is
where 
Example Question #2 : How To Find The Slope Of Perpendicular Lines
A line passes through points (–6,9) and (4,–4). Find the slope of the line that runs perpendicular to this line.
To find the slope of this perpendicular line, we need to first find the slope of the line that passes through points (–6,9) and (4,–4). Remember, the general formula for slope is 
The slope of the line passing through (–6,9) and (4,–4) is –13/10. To find the slope of the line that is perpendicular, just switch the sign and take the reciprocal of –13/10. This gives us 10/13. So 10/13 is the slope of that perpendicular line.
Example Question #1 : How To Find The Slope Of Perpendicular Lines
Find the slope of the line perpendicular to the line that fits the following points:
(3,5), (2,7), (0,11)
1) To find the slope of the perpendicular line, we must first find the slope of the line fitting the given points. Slope is equal to change in 
2) The perpendicular slope is the opposite reciprocal of the slope of the line to which it is perpendicular. So flip the original slope upside down and multiply by 
Perpendicular slope
Example Question #11 : How To Find The Slope Of Perpendicular Lines
What is the slope of a line that is perpendicular to
None of the other answers
Perpendicular lines have slopes that are negative reciprocals of one another. The slope of the given line is 
Thus, the slope of the perpendicular line must be 
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