By definition the control in a science experiment is a sample that remains the same throughout the experiment. The control must remain the same or equal at all times in order to receive accurate results. You can have as many controls as necessary to achieve results.
Graphs are often an excellent way to display your results. In fact, most good science fair projects have at least one graph. For any type of graph: Generally, you should place your independent variable on the x-axis of your graph and the dependent variable on the y-axis.
Please explain the gist of how to determine the function value when there is a graph presented... and also some functions of numbers. theres f(-2) f(2) stuff like that... I have to determine the value of them all using the graph given so i just need some basic help. If you have the book...