A list of the squares

The procedure square-list takes a list of numbers as argument and returns a list of the squares of those numbers.

(square-list (list 1 2 3 4))
(1 4 9 16)

Here are two different definitions of square-list . Complete both of them by filling in the missing expressions:

(define (square-list items)
  (if (null? items)
      nil
      (cons <??> <??>)))

(define (square-list2 items)
  (map <??> <??>))