(1) change to some other computer if it does not seem to work 
properly when you are entering some answers. 

(2) There are several ways WebAssign can ask you to enter 
the entries of a matrix. One is that boxes (arranged in 
an array fashion) are provided. In this case,

(i) the dimensions of the matrix can/need to be set/changed by 
clicking the arrows provided to the right and bottom of the matrix.

(ii) (in case you do not want to do (i) but the actual matrix
dimensions of the answer (e.g. (2x3)) is bigger than what appears 
in the screen (e.g. (3x3)), then DO NOT enter numbers in the 
non-existent/fictitious entries.

(3) The second way you will be asked to enter a matrix is by
actually typing in all the numbers by hand. In this case, 
the format is the following. To enter an mxn matrix, use:
[[row_1], [row_2], ...., [row_m]]
where row_i is the i-th row of the matrix, listed as a 
comma-separated list. For example, to enter the 2x3 matrix:
        | 1 2 3 |
        | 4 5 6 |,
then type: [[1,2,3], [4,5,6]]

(4) when entering functions such as sin, cos....,
use small letters only. Or you can also use the math palette provided.

(5) the space of row vectors is denoted by R_n;
the space of column vectors is denoted by R^n.

(6) as a rule of thumb, ALWAYS use EXACT expressions when 
entering your answers. They all can be entered by typing in
your answers or utilizing the math palette.
If approximations need to be used or are asked, 
then enter at least 3 decimal places.