Directed line segments can also be represented in ℝ3. instead of two coordinates like we use in ℝ2, we simply use three
to locate a point in space relative to the origin, denoted (0,0,0). thus, the vector ⃗ with initial point a(x1, y1, z1) and
terminal point b(x2, y2, z2) would have component form:
ab = 〈x2 − x1, y2 − y1, z2 − z1〉.