4. Rewrite the following code using a vectorized operation in a single calculation within an assignment statement. Demonstrate the equivalency by coding and running both in matlab. [r c] for ii size(mat); 1:r for jj= 1:0 mat(ii,jj) end mat(ii,jj)*2; end mat 5. Demonstrate the use of logical indexing to find the subvector of all scores less than 60 from a vector of scores [65, 36, 81, 68, 18, 3, 16, 59, 29, 25, 22, 95, 62, 98, 30, 34, 8, 77, 32, 74]. 6. The following is a recursive definition of an where a is any integer and n is a non-negative integer: an = 1 if n = 0 an = a* an-1 if n > 0 Write a recursive function that receives values of a and n as inputs and returns a" by using this recursive definition. You cannot use the ^ operator anywhere in your program use recursion instead