Which statement is always true for two distinct non-vertical lines in the Cartesian plane?
MATHEMATICS · Single correct · A Level · Mathematics · Coordinate geometry in the (x y) plane · Coordinate geometry in the (x y) plane
Problem
Which statement is always true for two distinct non-vertical lines in the Cartesian plane?
(a) If their slopes are equal, the lines intersect at exactly one point.
(b) If the product of their slopes is 1, the lines are perpendicular.
(c) If the product of their slopes is −1, the lines are perpendicular.
(d) If one line's slope is the reciprocal of the other's, the lines are perpendicular.