Consider the following quadratic models:
(1) y = 1 - 2x + x2
(2) y = 1 + 2x + x2
(3) y = 1 + x2
(4) y = 1 - x2
(5) y = 1 + 3x2
a. Graph each of the quadratic models, side by side, on the same sheet of graph paper.
b. What effect does the first-order term (2x) have on the graph of the curve?
c. What effect does the second-order term (x2) have on the graph of the curve?