1. Graphing in Vertex Form and Intercept Form

2.  What kind of functions are the following…?

3.   y = a(x – h) 2 + k  It is the graph of the parabola y = ax 2 translated horizontally h units and vertically k units.  The vertex is (h, k)  The axis of symmetry is x = h. Vertex Form

4.   1. Identify the vertex and plot it.  Ex: y = 3(x – 5) 2 – 8  Vertex: (5, -8)  Ex: y = -½ (x + 2) 2 + 4  Vertex: (-2, 4)  Ex: y = (x + 7) 2 – 1  Vertex: (-7, -1)  2. Draw the line of symmetry through the vertex.  3. Evaluate the function for values of x near the line of symmetry and plot those points. Graphing in vertex form

5.   Graph: y = ½(x – 3) 2 - 5 Example

6.   Use the calculator to graph. Notice anything?  y = 2(x – 3)(x + 6)  y = x(x + 4)  y = (x – 5)(x – 1)  If you know the x intercepts, you can plot them to help make your graph.  The vertex will have an x-value that is halfway between the x-intercepts. Intercept form

7.   y = a(x – p)(x – q)  The x-intercepts are p and q.  The axis of symmetry is halfway between (p, 0) and (q, 0).  The graph opens up if a is positive.  Example: graph y = -x(x – 4) Intercept form