Mathematics for IGCSE & O level - Coordinate Geometry (Section 3 - No. 10)
Which of the following sets of lines are perpendicular?
y = 2x and y = -1/2x + 5
y = 3x + 1 and y = 3x - 2
y = x and y = -x + 1
y = 4x - 1 and y = 1/4x + 2
คำอธิบาย
Perpendicular lines have negative reciprocal slopes. Therefore, pick the two pairs which satisfy this