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Parameters

Parameters are real values which can move in a fixed interval, e.g. between -5 and +5. The real value may be changed by moving a cursor with the mouse below the controls at the right of the geometrical representation. There are two kinds of parameters: formal and numeric parameters. Formal parameters have a formal name which is used in all exact calculations, and a numeric value which is used for all numeric evaluations. They can be used to do a CAS proof of a geometrical theorem, while displaying a figure. Numerical parameters have only their numerical value.

To add a new parameter, use the Edit menu of the geometry level. For example, add a level with f(x):=a*x^2+b*x+c then define 3 parameters named a, b, c and add the command plot(f(x)), then move one of them. You can also add a level mini:=solve(diff(f(x),x)) and M:=point(mini[0],f(mini[0])) to display the minimum. Note that the coordinates of M are displayed in terms of a and b in the subsession at the left. You must add a level with e.g. evalf(coordonnees(M)) to see the current value.



giac documentation written by Bernard Parisse