Multiply two vectors to get a number — the dot product. Tells you how aligned they are.
Component form
a · b = a₁b₁ + a₂b₂ + a₃b₃
Geometric
a · b = |a| |b| cos θ
If a · b = 0, the vectors are perpendicular.
Multiply two vectors to get a number — the dot product. Tells you how aligned they are.
If a · b = 0, the vectors are perpendicular.