Consider the graphs of the following functions:
How does the value of d effect the graph
of 
?
By looking at the graphs above, we see
that there is a shift to the right and the left. Focus your attention to the green graph, .
This is when d=0. There is no shifting, and it is symmetric about
the y-axis. Now, when the d-value is positive, we see that the
graph shifts d units to the right of the y-axis. When the d-value
is negative, we see that the graph shifts d units to the left
of the y-axis. This helps us in the study of quadratic equations.
We could now predict the direction as well as the amount of shift
from y-axis by the d value.