Presentation on theme: "4.2: Graphs of Quadratic Functions in Vertex or Intercept Form"— Presentation transcript:
1 4.2: Graphs of Quadratic Functions in Vertex or Intercept Form Objectives:To graph quadratic functions in vertex and intercept formTo rewrite a quadratic equation in standard, vertex, or intercept form
2 Graphing Quadratic Functions, II To graph y = a(x – h)2 + k :Use the a-value to determine or Plot the vertex (h, k)Graph the axis of symmetry x = hFind and plot at least two other function values and their reflectionsx- and y-intercepts?Draw a parabola through the points
3 Exercise 1 Graph First find the axis of symmetry Remember y = a(x – h)2 + kAxis of symmetryx= hAnd x = -2GRAPH X= -2
4 Exercise 1GraphNow find the vertex. (h,k)(-2,3) Plot the point.
5 Exercise 1 Graph Now find the vertex. (h,k) Pick two values for x and find its matching coordinate point for y.x=-1 y = -(-1+2)^2 + 3= -(1)^2 + 3= = 2Plot (-1, 2)
6 Exercise 1 Graph Now find again when x = 0 x=0 y = -(0+2)^2 + 3 = -(2)^2 + 3= = -1Plot (0, -1)