MATLAB can be extended with so called toolboxes. In general, these are collections of MATLAB functions that are tailored for special classes of problems. The `(Extended) Symbolic Math Toolbox' is an exception. To a great extent, this toolbox consists of ingredients from the computer algebra package MuPAD. MATLAB performs calculations with the aid of matrices. These are rectangular schemes of numbers, which are also called arrays. The `Symbolic Math Toolbox' is quite different from MATLAB itself, since symbolic calculations hardly make any use of arrays. For this reason it is important to know whether a function used is a MATLAB function or a `Symbolic Math Toolbox' function. This will not be completely clear at the outset, but it will become clearer after regular use of MATLAB.