Mathematics for IGCSE & O level - Coordinate Geometry (Section 3 - No. 34)
If a line has a gradient of -1/2, what is the gradient of a perpendicular line?
-2
2
1/2
-1/2
คำอธิบาย
Perpendicular lines have gradients that are negative reciprocals of each other. -1/(-1/2) = 2