True or False? If False, you should come up with a counterexample. If True, can you give a proof?
(a)
The zero vector is the only vector of length 0.
True False
(b)
If , then .
True False
(c)
If , then .
True False
(d)
If , then .
True False
(e)
If , then .
True False
(f)
If for some scalar , then and have the same direction.
True False
(g)
If , and are non-zero, and is parallel to , then and are also parallel.
True False
(h)
True False

Source

[Nicholson] W. Keith Nicholson, Linear Algebra with Applications, Lyryx 2021, Open Edition, Problem 4.1.21.