Originally Posted by

**skeske1234** State whether the following expressions are vectors, scalars, or meaningless.

I need help with these two.. I think personally, that my answers are right, but perhaps my reasoning is not valid because the back of the book has a diff answer.

Here is what I am thinking:

a) (**a** x** b**) + (**b** x **c**)

=vector + vector

=scalar NO it is a vector.

I say the answer is scalar because for example

(4,3,2) + (2,1,2)

=6+4+4

=14<<<< scalar NO it is a vector.

But the back says vector, what am i missing here?

b) (**a** x** b**) - **c**

=vector - vector

=scalar NO it is a vector.

I say the answer is scalar because for example

(1,2,3)-(3,2,1)

=-2+0+2

=0<<< scalar NO it is a vector.

But the back says vector, what did i do wrong here?

c) (**a** . **b**) - **c**

=scalar - vector

=scalar NO it is meanless.

I say the answer is scalar because for example

4-(4,3,2)

=4(-4,-3,-2)

=-16-12-8

=-36 <<< scalar

what did i do wrong here and what should the answer be?

**Note: bolded are vectors**