Naming Objects

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You can assign a certain name to an object when you create it using the Input Bar:

  • Points: In GeoGebra, points are always named using upper case letters. Just type in the name (e. g., A, P) and an equal sign in front of the coordinates or commands.
Example: C = (2, 4), P = (1; 180°)
  • Vectors: In order to distinguish between points and vectors, vectors need to have a lower case name in GeoGebra. Again, type in the name (e. g., v, u) and an equal sign in front of the coordinates or commands.
Example: v = (1, 3), u = (3; 90°)
  • Lines, circles, and conic sections: These objects can be named by typing in the name and a colon in front of their equations or commands.
Example: g: y = x + 3, c: (x-1)^2 + (y – 2)^2 = 4, hyp: x^2 – y^2 = 2
  • Functions: You can name functions by typing, for example, f(x) = or g(x)= in front of the function’s equation or commands.
Example: h(x) = 2 x + 4, q(x) = x^2, trig(x) = sin(x)
  • If you don’t manually assign a name to an object, GeoGebra assigns the names of new objects in alphabetical order.
  • You can create indices within the names of objects by using an underscore. For example A1 is entered as A_1 and sAB is entered as s_{AB}.

Reserved labels

There are a few labels you can't use for objects: x, y, z, xAxis, yAxis, zAxis.

In the symbol list of the input bar, you will find special characters for the following constants:

  • π - the circle constant pi
  • ℯ - the Euler number, e.g. for the exponential function ℯ^x
  • ί - the imaginary unit, e.g. for complex numbers like z = 3 + ί

When the variable names e resp. i are not used yet, they are automatically read as ℯ resp. ί for convenience.

See also Labels and Captions.

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