## GeoGebra 4.0 Sneak Peek 5: The Computer Algebra System

This is the fifth post of the GeoGebra 4.0 Sneak Peek Series.

One of the major enhancements of GeoGebra 4.0 is the integration of Computer Algebra System (CAS). The GeoGebra CAS window can be viewed by clicking the **View>CAS **from the menu bar. The CAS toolbar includes the following tools as shown in the first figure: **Evaluate** (exact evaluation), **Numeric** (numeric evaluation; e.g. sin(1)), **Keep Input**, **Factor**, **Expand**, **Substitute**, **Solve**, and **Differential/ Integral**.

You can enter expressions/equations at the CAS window (see black texts below) and click the buttons at the toolbar to perform a command. The output of a command is shown in blue texts. Line 1, for example, used the *Evaluate* button to simplify 2*x* + 4*x* – 3*y* + 2*y*. » Read more