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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