Well defined Vector operations

[Whiz]

Homework Statement

Given that u , v and w are vectors, which of the following are well defined operations? Find ALL correct answers

A. (3u X v) X (5u X w)
B. (3u X v) X (5u . w)
C. (3u X v) . (5u . w)
D. (3u X v) . (5u X w)
E. none of the above

X = Cross Product
. = Dot Product


I'm just wondering what this question means by "Well Defined Operations". If anyone knows, can you help me out?

Thanks.

 

[rootX]

It is providing different cases and in some you are taking dot product of scalar and vector, cross product of scalar and vector etc. You need to tell them if it is valid.