### LON-CAPA Help

Which Elements you use depends on the type of problem you want to make.

- Background Plot - This places a static curve on the graph of your choosing. It can be labeled, moveable or fixed, and any color desired. Only the right hand side of the function you want displayed is necessary. For example, entering
*x*+2 will display the line *y*=*x*+2. The syntax must be syntax recognized by GeoGebra. To test syntax for Geogebra directly, visit http://www.geogebra.org/webstart/geogebra.html .
- Spline - At least one spline is necessary for a graph problem. These splines are what will be adjusted and analyzed to solve the problem.
- Object - This places a point in the applet. Generally intended to be used with Vectors to create problems involving Free-Body Diagrams or any other points that vectors (or arrows) connect to and from.
- Vector - This creates a vector (or arrow) in the applet. Generally intended to be used with Objects to create problems involving Free-Body Diagrams or to establish connections between Objects.