w22list.erl

-module(w22list).
-export([take/2, nub/1]).

-spec take(integer(), [T]) -> T.
take(0, _L) -> [];
take(I, L) when I < 0 orelse I > length(L) -> L;
take(I, [H|T]) ->
    [H | take(I-1, T)].

nub(L) -> nub(lists:sort(L), []).
nub([H|[]], ACC) -> lists:reverse([H | ACC]);
nub([H|T], ACC) ->
    case hd(T) of
        H -> nub(T, ACC);
        _ -> nub(T, [H | ACC])
    end.

[H|[]] could be written as [H]

But your code changes the order of elements.