Scalar Product
Multiplying corresponding terms and getting a sum of the products
i.e. (a₁ x b₁) + (a₂ x b₂) (+ (a₃ x b₃)) = Scale Product = a.b
Acute angle between two vectors
Cosθ = a.b/(|a||b|)
Scalar product of perpendicular lines
a.b = 0 (a and b being the vectors of said lines)
Vector Equation of a Straight Line - position vector and parallel
r = a + λd
→
What does the vector AR mean?
→
AR = r - a, where r and a are position vectors of R and A respectively
Vector equation of a Straight Line - two points
r = c + λ(d -c)
Vector equation of a plane
r = a + λb + μc
Cartesian equation of a line
If a = (a1 a2 a3) and b = (b1 b2 b3), r = a + λb:
x - a1)/b1 = (y-a2)/b2 = (z-a3)/b3 (= λ