function y is defined as

y$=\{$cos$($x$)$ if x $=<0$

$-$sin$($x$)$ if x$>0$

determine the values of of y in a vector called z for x values from $-2$ to $2$ in steps of $0\mathrm{.}2.$

a$.$ display the values of vector z

b$.$ determine and dispaly sum of values of the vector z