# CAS View

From GeoGebra Manual

Revision as of 14:13, 7 February 2012 by Christina.biermair (talk | contribs)

## Basic input

- Enter: evaluate input
- Ctrl + Enter: check input but do no evaluate input, e.g.
*b + b*stays*b + b*. Note that assignments are always evaluated, e.g. a := 5 - In an empty row type
- Space bar for previous output
`)`

for previous output in parentheses`=`

for previous input

- Suppress output with a semicolon at the end of your input, e.g.
`a := 5;`

## Toolbar

- Clicking a button in the toolbar applies a command to the currently edited row
- You can select part of the input text to only apply the operation to this selected part

## Variables

### Assignments & Connection with GeoGebra

- Assignments use the := notation, e.g.
`b := 5`

,`a(n) := 2n + 3`

- To free up a variable name again, use
`Delete[b]`

or`b :=`

- Variables and functions are always shared between the CAS view and GeoGebra if possible. If you define
`b:=5`

in the CAS view, then you can use*b*in all of GeoGebra. If you have a function`f(x)=x^2`

in GeoGebra, you can also use this function in the CAS view.

**Note:**

The output will always be just the term AFTER the :=, e.g. if you type

*b:=5*the output will be*5*.### Row References

You can refer to other rows in the CAS view in two ways

- Static row references insert text from another row, so your input is changed.
`#`

inserts the previous output`#5`

inserts the output of row 5

- Dynamic row references use text from another row, but don't change your input.
`$`

inserts the previous output`$5`

inserts the output of row 5

## Equations

- Equations are written using the simple Equals sign, e.g.
`3x + 5 = 7`

- You can perform arithmetic operations on equations, e.g.
`(3x + 5 = 7) - 5`

subtracts 5 from both sides of the equation. This is useful for manual equation solving. `LeftSide[3x + 5 = 7]`

returns*3 x + 5*and`RightSide[3x + 5 = 7]`

returns*7*

## Commands and Tools

For a complete list of commands and tools see CAS Commands and CAS tools.