Direction Numbers of a Line in 3D
Direction Numbers(Direction Ratios) in 3D Geometry ———————————————————————————————— The term ‘Direction Numbers’ is generally introduced in 12th grade topic 3D geometry in CBSE syllabus. And here’s how it is defined. Any three numbers which are proportional to the direction cosines of a vector are called the direction numbers of the vector. That’s the definition of direction numbers that you will find in most indian standard textbooks, and in many online supplementary sources. This statement is followed by expressing the same thing in mathematical language. If a, b, c are direction numbers of a vector, then a = s cos 𝜶, b = s cos 𝜷 , c = s cos 𝜸 for any s ∈ R + If from this you are able to understand what direction numbers are then great! But in my case it didn’t really sink in at first. And the worrying part was when I found that their usage comes up almost everywhere in the topic. It took some time for me to get comfortable with them. In thi...