- #1
tirwit
- 16
- 0
I'm reading Riley's "Mathematical Methods for Physics and Engineering" and I came across this expression about vector spaces:
"A set of objects (vectors) a, b, c, ... is said to form a linear vector space V if the set is closed under commutative and associative addition (...)"
What I don't understand is: what does commutative and associative addition have to do with a closed set?!![Confused :confused: :confused:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
"A set of objects (vectors) a, b, c, ... is said to form a linear vector space V if the set is closed under commutative and associative addition (...)"
What I don't understand is: what does commutative and associative addition have to do with a closed set?!