To create a matrix
The entries can be any valid mathematical expression. Both real and complex numbers are legitimate entries, as well as algebraic expressions.
You can move about in a matrix with the arrow keys, by pressing TAB and BACKTAB, and by using the mouse. Pressing SPACEBAR will move your insertion point through the mathematics or out of the matrix.
A 2×2 matrix can be entered from a Windows keyboard with CTRL + A. You can also create an m×n matrix using Fill Matrix from the Matrices submenu.
To create a matrix with Fill Matrix
The matrix will appear inside the brackets, filled with the entries you chose. These choices are discussed in the next few paragraphs.