# Naming Objects

From GeoGebra Manual

Revision as of 13:50, 26 July 2011 by Andrea.duringer (talk | contribs)

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°)`

**Note:**Complex numbers get displayed as points, whether they are named with upper or lower case letters.

- 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 A
_{1}is entered as`A_1`

and s_{AB}is entered as`s_{AB}`

.

## Reserved labels

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

Once you create object dependent on imaginary unit *i* or Euler number *e*, auxiliary object called *i* (resp. *e*) is created. From that moment you cannot use this label for other objects. On the other hand, if you define for instance *e=3*, you will have to use special **e** character from the symbol list to get Euler number.

See also Labels and Captions.