$4.$ Using,Create a row vector vec that the elements start from $-10$ to $10,$ by incremental $5,$ using colon operator.

Then do the followings:

$($a$)$ Create a new vector sub vec by extracting the last $3$ elements from vector vec.

$($b$)$ Change the value of last element of vec such that the value of last element is calculated using function

sin$().$