Stage 30 · Analytic Geometry

30.3.2 Perpendicular: Slopes Are Negative Reciprocals

30.3 Two Lines: Parallel, Perpendicular, Intersection, and Distance

Point 2 of 5

30.3.2 Perpendicular: Slopes Are Negative Reciprocals

Core idea

Pin two lines into a right angle and as one climbs the other must drop to match, so k₁·k₂=−1.

Module goal. Study how lines relate to each other, judge their positions, find intersections, and compute distances, finishing the toolbox for lines.
eastmath.com · 30.3 Two Lines: Parallel, Perpendicular, Intersection, and Distance · 30.3.2 Perpendicular: Slopes Are Negative Reciprocals