Answer:

It is hard to do anything but guess. My guesses are:

For the arrows in the picture, how many feet in the X direction is the tip from the tail? 3 ft
How many feet in the Y direction is the tip from the tail? -4 ft
How many feet in the Z direction is the tip from the tail? -3 ft

Vectors and Frames

Cupola Image with Sunlight vectors and Coordinates

So the vector that gives the intensity and direction of sunlight in the picture is:

The column matrix represents the vector using our chosen coordinate frame. The column matrix is not the vector. If we had picked a different coordinate frame, the vector in the physical scene would be the same, but its representation using the new frame would change.

The next chapter will continue this discussion.

QUESTION 17:

(Review: )

A point has only one property: ______________ .
A vector has two properties: ______________ and _____________ but does not have _____________.