Key Feature: y - intercept is (0, -3) where the graph crosses y (f(x)) - axis.
Let x = 0 f(0) = 0² + 2(0) - 3 = 3
Key Feature: x - intercepts are (-3, 0) and ( 1, 0) where the graph crosses x - axis
Let f(x) = 0, x² + 2x - 3 = 0 ⇒ (x + 3)(x - 1) = 0 ⇒ x + 3 = 0 or x - 1 = 0 ⇒ {-3, 1}
Key Feature: upward (∪-shaped) parabola because "a" of y = ax² + bx + c is greater than 0
Key Feature: vertex is (-1, -4) the vertex is also a minimum because the graph is turned upward making the vertex the lowest point of the graph
x-vertex = b/(-2a) ⇒ 2/(-2×1) = -1
y-vertex = (-1)² + 2(-1) - 3 = -4
Key Feature: axis of symmetry equation is x = -1 ... found using same formula as the x - vertex
Key Feature: domain is all real numbers and range is all real numbers greater than or equal to -4
