??????2?????????????????
?????3?£??????????????????????????????????????λ?3?? ?????? ?????? ???????????壬????????μ?????
????????????????
??????? ???????? ????0 ???10 ????????? ????????????????????????????? ???????? ????50 ???20 ????????????е???????????2?? ??????????????????????????? ???????? ????0 ???20 ?????﹥????1???????????1/4????
??????? ???????? ????0 ???10 ????????? ?????????????????????????
????? ???????? ????50 ???20 ????????????е???????????2?? ???????????????????????
???? ???????? ????0 ???20 ?????﹥????1???????????1/4????