go to previous page   go to home page   go to next page

What do you think might be true about:

a  ·  b  ·  c

Answer:

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).


Mixed Types == Trouble

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.


QUESTION 13:

What is 2( -1, 2)T · ( 4, 1 )T ?