Graph quadratic functions by means of: plotting sets of points, finding points of intersection with axes and finding the equation of axis* of symmetry and the coordinates of the vertex
Example 1. - plotting sets of points
![Picture](/uploads/1/1/5/3/11531538/892919.png)
Graphing it this way will require more time but will result in a greater accuracy in the graph. For example if the equation given is: y = x squared. This process is basically letting x be a number and finding y. if x = 1, then y = 1. If x = 2 then y = 4. It might be helpful if a table is drawn showing the x and y values. The individual sets of points can then be plotted onto a graph and joined together.
Example 2. - finding points of intersection with axes
![Picture](/uploads/1/1/5/3/11531538/1424122.png)
This process of graphing is similar to the previous method but only a few points need to be plotted. For example y = x squared - 1. In this case, we let y be 0 and find the value of x (which is -1 or 1) and the value of y if x = 0 (which is -1). Therefore we have 3 points: (-1, 0), (1, 0) and (0, -1). These points can then be graphed into a parabola.
Example 3. - finding the equation of axis of symmetry and the coordinates of the vertex
![Picture](/uploads/1/1/5/3/11531538/1372004.png)
This process requires a formula for finding the vertex which is shown on the left for the equation: ax squared + bx + c = 0. The axis of symmetry is just the line cutting the graph in half. For example: y = x squared - 2. Using the formula, the vertex would be at (0, -2) and the axis of symmetry would be x = 0. (the line that cuts it in half)
Interactive parabola grapher!!