1.  The following graph shows bakery profits from bread sales. How do you determine the equation of the quadratic relation from its graph?

3.  The amount of gasoline that a car consumes depends on its speed. Below is the relationship between speed and fuel consumption for a particular car. Speed (km/h)102030405060708090100110120 Gas Consumed (L/100km) 9.28.17.47.26.46.15.95.86.06.37.58.4

4. Speed (km/h)102030405060708090100110120 Gas Consumed (L/100km) 9.28.17.47.26.46.15.95.86.06.37.58.4

5.  We can see the general shape of a parabola here, but it’s not perfect  Why? Because these is modeling a real-life situation with real data, not perfect data

6.  The curve that models this data is:  y = 0.0009(x – 75) 2 + 5.8  Not pretty, but it’s accurate and realistic

7.  If you know the coordinates of the vertex (h, k) and one other point on a parabola, you can determine the equation of the relation using y = a(x – h) 2 + k