Match each equation to what it describes

Exercise and reference answers

Matching pairs

Left
r = a + λb
Right
line through a point, parallel to a vector
Left
r = a + λ(b − a)
Right
line through two given points
Left
(x−x₁)/l = (y−y₁)/m = (z−z₁)/n
Right
Cartesian form using direction cosines
Left
cos θ = |b₁·b₂| ÷ (|b₁||b₂|)
Right
angle between two lines

The vector and Cartesian forms the chapter gives for a line. Source: syllabus Maths Part II, Ch 11 Three Dimensional Geometry.