# Naming Objects

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)`
Note:
• 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.