AlgebraEasy–MediumProperties of a vertical line
Algebra practice question
In the xy-plane, line ℓ has equation x = 5. Which of the following statements about line ℓ is true?
- A. Line ℓ is perpendicular to the x-axis.Correct
- B. Line ℓ has slope 5.
- C. Line ℓ passes through the origin.
- D. Line ℓ is parallel to the x-axis.
Answer: A. Line ℓ is perpendicular to the x-axis.
x = 5 is a vertical line: every point has x-coordinate 5, so it meets the x-axis at a right angle.
Why the other answers are wrong
- B. Line ℓ has slope 5.
- A vertical line's slope is undefined.
- C. Line ℓ passes through the origin.
- The origin has x = 0, not 5.
- D. Line ℓ is parallel to the x-axis.
- A vertical line is perpendicular, not parallel, to the x-axis.
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