Precalculus Section 1.7 Define and graph quadratic functions Any function that can be written in the form: y = ax 2 +bx + c is called a quadratic function. It’s graph is called a parabola. Consider the graphs of the quadratic functions: y = x 2 y = 2x 2 y = -2x 2 y = x 2 – x – 6

The graph of y = ax 2 +bx + c has an axis of symmetry of x = -b/2a, roots(x intercepts) which are the solution of ax 2 +bx + c= 0, a y-intercept of c, and the x value of the vertex is x = -b/2a. If a>0 the parabola opens up, if a<0 the parabola opens down. Find the x and y intercepts, axis of symmetry, the vertex, and sketch the graph of y = -x 2 + 4x - 3

Graph f(x) = 2x 2 + 5x - 12

Vertex form of a quadratic function y = a(x-h) 2 + k (h,k) is the vertex, x=h is the equation of the axis of symmetry. Find the vertex, intercepts, axis, and sketch the graph of y = -1(x+2) 2 + 3

Graph f(x) = 2(x-4) 2 - 5

Find the equation of the parabola with a vertex of (4,8) and passing through the point (2,6).

The path of a projectile is a parabola. A ball is thrown upward so that its height h in ft after t seconds is given by h = -16t t + 8. Find: a. Its height after 1.3 seconds b. The time it reaches its maximum height. c. The maximum height. d. The time when it strikes the ground.

Assignment Page 41 Problems 2,4,7,12,14,16,18,21,22,29,32,35