To do
Work out some concrete problems, especially checking for angles, lengths, perpendicularity.
Given vectors
work out a formula for
for which
is perpendicular to
. The resulting vector
is said to be the projection of
on
. See why it is so, by examining some plane examples. In general, it makes a similar sense in higher dimensions as well. In general, the dot product does behave like a commutative multiplication with nice distributive properties over addition:
This means identities like (
).
.
The main thing which does not make sense is a dot product of three vectors, since the product of two produces a scalar and not a vector!
Special attention should be given to problesm 18-24 on pages 18,19.
Also do the problems from the WQS system based on Chapter 1.2.