I intuitively accepted that there is an unique representation of any point in a 3d space by linear combination of 3 mutually perp. vectors. But now I'm wondering is this an axiom or a theorem?
If theorem where can I find a proof of this?
Just so that it is easier for you to explain - I'm a highschool student who knows vector addition, subtraction, scalar product and vector product and some basic knowledge or 3d geometry line equations of lines and planes.