Stage 29 · Spatial Vectors & Solid Geometry

29.2.5 The Coordinate Formula for the Dot Product

29.2 Putting a Coordinate Grid on Space — The Basis Theorem and Coordinates

Point 5 of 6

29.2.5 The Coordinate Formula for the Dot Product

Core idea

Multiply matching components and add them up — a·b=x₁x₂+y₁y₂+z₁z₂ — with no need to look at a picture anymore.

Module goal. Use three non-coplanar vectors as a "skeleton" to describe every vector in space, then set up a 3D coordinate system that turns both vectors and points into three numbers, laying the groundwork for the calculations ahead.
eastmath.com · 29.2 Putting a Coordinate Grid on Space — The Basis Theorem and Coordinates · 29.2.5 The Coordinate Formula for the Dot Product