?? ???? ??????? ????????? ???? ????? ????? ????? ?????? ???? ??????? ????? ???????. ????? ?????? ????? ????????? ????? ?????? ????? ????? ????? ?? ???????. ???? ????? ????? ????? ??????? ?????? ????? ?? ?????? ????? ??????? ???????? ??? ????? ?? ??? ?? ??? ??????? ???? ?????? ?? ?????. ???? ??? ?

???? ??? ????? ?????? ????? ??????? ??????? ??????? ??????? ??????? ???? ?????? ??? ????????: ?² –??–?=? ?? ??? ??????? ???? ??????? ???? ??????? ??? ????? ?????? ????? ??????? ??????? ??????? ??????? ?????? ???????? ???? ???? ??????? ??? ???? ???????? ??????? ?????? ???????? ?? ?????? ??? ?????