All GMAT Math Resources
Example Questions
Example Question #11 : Lines
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 #12 : Lines
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 #13 : Lines
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 #15 : Lines
Which of the following lines is perpendicular to ?
None of the lines is perpendicular
Two lines are 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 #16 : Calculating Whether Lines Are Perpendicular
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
Example Question #1 : Understanding Rays
Refer to the above figure. and which of the following are opposite rays?
Opposite rays begin at the same endpoint; their directions are opposite each other. Since has endpoint , we are looking for the ray that has endpoint and goes in the opposite direction - this ray is .
Example Question #2 : Understanding Rays
Refer to the above figure. Which of the following is another name for ?
None of the other choices is correct.
A ray can be named with two letters, the first of which must be its endpoint and the second of which can be any other point on the ray.
has endpoint . The only other marked point on the ray is , so the correct choice is .
Example Question #1 : Understanding Rays
A ray starts at the point and has a positive slope of . In which quadrants does some part of the ray lie?
A ray starts at a single point and then continues in a straight line infinitely in some direction. The given ray starts at the point , which is in quadrant , so we immediately know this must be included in the answer. The ray has a positive slope of , which means the next point is , followed by , , , , and so on. By plotting these points we can visualize that the ray starts in quadrant , crosses through quadrant , and then continues infinitely into quadrant , without ever crossing through any part of quadrant . The answer, therefore, is the following three quadrants:
Example Question #2 : Understanding Rays
In the above figure, which two rays have as their union ?
and
and
and
and
and
and
An angle, by definition, is the union of two rays with the same endpoint. Their common endpoint is the vertex of the angle, which is always named by the middle letter of a three-letter angle name. Therefore, we are looking for two rays with endpoint . Since the first letter of the name of a ray is always its endpoint, we are looking for two rays with as the first letter in their names. This makes and the correct choice.