1. Quadratic functions A polynomial function of degree two

2. Definition of Quadratic function Let a, b, and c be real numbers with a not equal to zero. Then the equation at the right is called the quadratic function.

3. Standard form of a quadratic function The quadratic function at the right is said to be in standard form. The graph of f is a parabola whose axis is the vertical line x=h and whose vertex is the point (h, k) If a>0 , the parabola opens upward, and if a<0, then the parabola opens downward.

4. Changing a quadratic function to standard form In order to change a quadratic function to standard form from general form you will need to complete the square. See Example 2 on page 139 and Example 3 on page 140.

5. Finding quadratic functions given the graph