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Example Questions
Example Question #2 : Calculating Whether Lines Are Perpendicular
A given line has a slope of
. What is the slope of any line perpendicular to
?
Not enough information provided
In order for a line to be perpendicular to another line
defined by the equation
, the slope of line
must be a negative reciprocal of the slope of line
. Since line
's slope is
in the slope-intercept equation above, line
's slope would therefore be
.
Given that we have a line with a slope
, we can therefore conclude that any perpendicular line would have a slope
.
Example Question #3 : Calculating Whether Lines Are Perpendicular
Which of the following lines are perpendicular to ?
Two answers are perpendicular to the given line.
Two answers are perpendicular to the given line.
In order for a line to be perpendicular to another line
defined by the equation
, the slope of line
must be a negative reciprocal of the slope of line
. Since line
's slope is
in the slope-intercept equation above, line
's slope would therefore be
.
Since in this instance the slope ,
. Two of the above answers have this as their slope, so therefore that is the answer to our question.
Example Question #4 : Calculating Whether Lines Are Perpendicular
Do the functions and
intersect at a ninety-degree angle, and how can you tell?
It is impossible to determine from the information provided.
Yes, because and
have the same y-intercept.
No, because and
never intersect.
Yes, because the slope of is the reciprocal of the slope of
and it has the opposite sign.
No, because and
have different slopes.
Yes, because the slope of is the reciprocal of the slope of
and it has the opposite sign.
If two lines intersect at a ninety-degree angle, they are said to be perpendicular. Two lines are perpendicular if their slopes are opposite reciprocals. In this case:
The two lines' slopes are reciprocals with opposing signs, so the answer is yes. Of our two yes answers, only one has the right explanation. Eliminate the option dealing with -intercepts.
Example Question #5 : Calculating Whether Lines Are Perpendicular
Find the slope of a line that is perpendicular to the line running through the points and
.
Not enough information provided.
To find the slope of the line running through
and
, we use the following equation:
The slope of any line perpendicular to the given line would have a slope that is the negative reciprocal of , or
. Therefore,
Example Question #391 : Geometry
Which of the following lines is perpendicular to ?
Not enough information provided.
Given a line defined by the equation
with a slope of
, any line perpendicular to
would have a slope that is the negative reciprocal of
,
. Given our equation
, we know that
and that
.
The only answer choice with this slope is .
Example Question #632 : Problem Solving Questions
Which of the following lines is perpendicular to
Two of the answers are correct.
Two of the answers are correct.
Given a line defined by the equation
with a slope of
, any line perpendicular to
would have a slope that is the negative reciprocal of
,
. Given our equation
, we know that
and that
.
There are two answer choices with this slope, and
.
Example Question #391 : Geometry
A given line is defined by the equation
. Which of the following lines would be perpendicular to line
?
Not enough information provided
For any line with an equation
and slope
, a line that is perpendicular to
must have a slope of
, or the negative reciprocal of
. Given
, we know that
and therefore know that
.
Only one equation above has a slope of :
.
Example Question #14 : Lines
What is the slope of a line that is perpendicular to
For any line with an equation
and slope
, a line that is perpendicular to
must have a slope of
, or the negative reciprocal of
. Given the equation
, we know that
and therefore know that
.
Example Question #11 : Lines
Which of the following lines is perpendicular to ?
Two lines are perpendicular
None of the lines is perpendicular
Two lines are perpendicular
For any line with an equation
and slope
, a line that is perpendicular to
must have a slope of
, or the negative reciprocal of
. Given the equation
, we know that
and therefore know that
.
Given a slope of , we know that there are two solutions provided:
and
.
Example Question #633 : Problem Solving Questions
What is the slope of a line perpendicular to that of
First, we need to rearrange the equation into slope-intercept form. .
Therefore, the slope of this line equals
Perpendicular lines have slope that are the opposite reciprocal, or
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