2022全程班高分必刷800题答案解析新浪微博@考研数学周洋鑫12022年全程班高分必刷800题作业答案800题答案勘误题目:86、99、216、241、247、351、353、361、366、369【86】错误解析:正确解析:【99】错误解析:方程两端同时对x求导:223333'0xyyy即221'0xyyy①令'0y得21x代入原方程得1,1xy或1,0xy正确解析:方程两端同时对x求导:22'3333'0xyyy即22'1'0xyyy①令'0y得21x代入原方程得1,1xy或1,0xy【216】错误解析:322223201sin22xxxdxxxdx2022全程班高分必刷800题答案解析新浪微博@考研数学周洋鑫2正确解析:32222301sin22xxxdxxxdx【241】错误解析:故:2sinsinsin1cosxxfxxdxdxAxdxx222200sinsin2021cos21cosxxxAdxdxxx22001dcosarctancos1cos2xxx则221cos2xxfx正确解析:故:2sinsinsin1cosxxfxxdxdxAxdxx2200sinsin2021cos21cosxxxAdxdxxx22001dcosarctancos1cos2xxx则221cos2xxfx【247】错误解析:1001xxnnnnnFxtfxtdtfxtdtn,令nnxtu则01nxfudun正确解析:1001xxnnnnnnFxtfxtdtfxtdtn,令nnxtu则2022全程班高分必刷800题答案解析新浪微博@考研数学周洋鑫301nxfudun【351】错误解析:当,2,0xy时,2424,,0151715ABCBAC,取极小值;当16,,07xy时,21615,,15,0121ABCBAC,取极大值.正确解析:当,2,0xy时,244,0,01515ABCBAC,取极小值;当16,,07xy时,215,0,15,0ABCBAC,取极大值.【353】错误解析:边界内:'222221001xfxxyxyxy或'224222002yfyyxyxyx或0,0不在区域内部,舍去;2x,1y2,12,12,12,12ffff边界①上,20,22,,yxfxyx此边界上的最小值为0,00f,最大值2,02,04ff边界②上,设:222222,,24Fxyxyxyxy'22220xFxxyx①'24220yFyyxy②'2240...