"Show" that the direction cosines of a vector satisfies
$$\cos^2 \alpha + \cos^2 \beta + \cos^2 \gamma = 1$$
I am stumped on these things:
- "SHOW" that the direction cosines corresponds to a given vector to satisfy the relation above. ----> How do you "show" this? What does this mean? Does this mean to use the direction cosines of a vector?
- I'm sure this is a proof but I don't know what the end result would look like or better, what I am expected to learn from this proof.
I am not looking for a mere answer but really an in-depth explanation of the problem.
Greatly appreciated. :)