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.