Exercise $1$

Here are the matrices, A$,$ B$,$ and C:

$2$

$6$

$-2$

$8$

$7$

$-11$

$3$

$18$

$9$

A

$2$

$-4$

$-2$

$8$

$5$

$-11$

$3$

$-2$

$9$

B

$14$

$3$

$-2$

$6$

$3$

$17$

$-4$

$7$

$3$

C

Using logical indexing, do the following:

Double all elements in A that are less than $5.$

Set all matrix elements in B to their absolute value. $($Hint: select only the negative elements and multiply them by $-1.)$

Identify the locations in A that are greater than $1$; set all matrix elements in C that are in the same locations to be $0.$

Each of these operations should only require one line of code $($though you can also do them with multiple lines and an intermediate variable for the indexing result if you want to$).$