QUESTION 19:
- point B = ( 4.75, 6.23 )
- point A = ( 1.25, 4.03 )
What is the displacement from point A to point B?
By subtracting points:
Emily - Amy = ( 2, 2)T - ( 8, 4)T = ( -6, -2)T.
Of course by counting squares of the graph paper you will get the same answer.
With the story problem, there is a temptation to avoid negative numbers and to incorrectly compute the displacement. But it is perfectly OK to have negative displacements; the "negative" part just shows the direction:
Another thing to keep in mind is that the elements of a column matrix are
real numbers.
Examples often use integers, but that is just to make things
easy.
There is nothing wrong with the column matrix
What is the displacement from point A to point B?