do questions 2 and 4 in sml language

Exercise 2 Write a function cuber of type real -> real that returns the cube of its parameter Exercise 3 Write a function fourth of type 'a list -> 'a that returns the fourth element of a list. Your function need not behave well on lists with less than four elements. Exercise 4 Write a function min3 of type int . int . int -> int that returns the smallest of three integers