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	DESPERATELY SEEKING THE LOST GRAPH
	3rd year of secondary education.

1. A FIRST GLANCE

You can form different graphs in this window and the following windows by changing the parameter "g". There aren't any reference numbers on these graphs as all we are interested in at the moment is their shape.

1.- Change the value for the parameter "g" and look at the different graphs that appear on the electronic board. Copy them into your notebook.

2.- Which of the graphs in the window do you think corresponds to the following table of values about the amount of electricity used in a house? Copy this table into your notebook and draw the graph you think corresponds to it alongside the table.

KW/hour	0	100	200	300	400	500
Amount (euros)	10.80	12.60	14.40	16.20	18.00	19.30

3.-Do the same for the following table of values, which illustrates the distance covered by a vehicle against the time:

Distance (Km)	300	250	200	150	100	0
Time (h)	0	1	1.5	2	2.5	3

2. STILL LOOKING

As was the case in the window above, different graphs can be formed by changing the corresponding parameter in the following window.

4.- Visualise each of the graphs and draw them in your exercise book.

5.- Copy the following table, which shows the number of bacteria produced in a culture against the time. Match it to one of the graphs you have just seen.

Bacteria	4	8	16	32	64	128
Time (min)	0	10	20	30	40	50

6.- Repeat the previous activity for the following table of values, which shows the number of plants that germinate in a seedbed.

Plants	1	2	4	8	16	16	16	16
Time (days)	0	1	2	3	4	5	6	7

3. THE SEARCH GOES ON

In the following window more complex graphs than those seen up until now will appear. The parameter "g" still represents the same thing.

7.- The following table of values shows the variation in speed of a fairground attraction ride during stationary movement:

speed (m/s)	0	10	20	10	0	10
time (s)	0	5	10	15	20	25

Match this table to one of the graphs in the window. Copy both the table and graph into your exercise book.

8.- The following table of values shows the variation in the water flow of a fountain and the time needed to fill a nearby deposit. Match the data to one of the graphs in the window.

water flow (l/min)	10	20	30	40	50	60
time (min)	600	300	200	150	120	100

9.- Make up another table of values, which relates other magnitudes, and that could be associated to the third graph that appears in the window.

4. THE FINAL QUEST

In the following window there are some graphs which are somewhat different to the other graphs we have seen so far. Change the value of "g" to see them one by one.

10.-Which of the three graphs in the window do you think corresponds to the following table of values, that shows the flight of a balloon? Copy the table and its corresponding graph into your exercise book.

height (m)	10	10	50	50	30	0
time (min)	0	10	30	45	50	55

11.- Repeat the process for the following table of values, which shows the temperature of a substance being heated up:

temperature (ºC)	0	20	20	60	60	80
time (min)	0	5	12	24	36	50

12.- Make up a table of values with two related variables for each graph which is not connected to any of the data given so far. Write them into your exercise book along with their graphs that you haven't copied down yet.

	Josep Mª Navarro Canut

	ProyectoDescartes.org. Year 2013