备受关注的第17届“希望杯”全国数学邀请赛虽已落下帷幕,但是为广大师生带来了很多既贴近教材,又有创意的优秀试题．本文给出高二 2试解答题的又一解法,供读者学习参考． Although the 17th “Hope Cup” national mathematics invitational tournament, which has attracted much attention, has come to an end, it has brought many outstanding questions that are both close to the teaching materials and creative. This article gives another solution to the problem of the second year of the second test, for readers to learn reference.