a$)$ Create the matrix $A$ by first creating a matrix of all $0\text{'}$s$,$ then putting in the

$-2\text{'}$s on the main diagonal and $1\text{'}$s on the first upper and lower diagonals. Solve

$Ax=b$ using backslash, and time it using 'tic' and 'toc'. Hint: Using the 'diag'

command can help here.

b$)$ Repeat the process, but using the sparse matrix format for A$.$ You can do

this inefficiently using the 'sparse' command to turn your matrices from part

a$)$ into sparse format. A much better way to do this is to create the matrix

using the 'spdiags' command. The syntax to do this can be found in the help

documentation of 'spdiags' $($type "help spdiags" on the command line$),$ Is there a

timing difference between solving sparse and full matrices using backslash? How

much?