What do you think might be true about:

a · b · c

It makes no sense. Remember that the dot product of two vectors (or column matrices) makes a real number. There is no such thing as the dot product between a real number and a vector (or column matrix).

There is no such thing as the dot product between a real number and a column matrix.

a · b · c= real· c(garbage)

or:

a · b · c=a ·real (garbage)

When dealing with dot products, keep track of the types of operands and results, as illustrated by the previous question.

What is 2( -1, 2)^{T} **·** ( 4, 1 )^{T} ?