Will |v| = √(v • v) ever be negative? No, since length is always zero or positive.
Will it ever be zero? Yes, when v is the zero vector.
Another property of the dot product is:
(au + bv) • w = (au) • w + (bv) • w, where a and b are scalars
Here is the list of properties of the dot product:
(Trick Question: ) What is u • v • w ?