第二章：一元函数微分【公众号：小盆学长】免费分享.pdfVIP免费

【解】)(xf1x0x在和不可导,故选（C）xnnxnnexxxf,,1maxe||1lim)(0e0111xxxxx,maxlim121iminnmnnnaaaa),,2,1(0miai其中.1)(212dtexfxt21x1y224416)(,2)(xxxexfexf)(1)(xfydydxxfdxdy])(1[)(【解】知，时233188)]21([)21()1(eeeff)(1)]([)(2xfxfxf由【解】)1)(2(11211)(2xxxxxf])2(1)1(1[3!)1()(11)(nnnnxxnxf)2111(311xxaxxxxxf432)(234)12)(2)(1(24664)(23xxxxxxxf0)(xf.1,21,2xxx【解】令,则令,得,4)1()2(aff4aaf1617)21(axxxxxf24683)(234)1)(2)(1(1224122412)(23xxxxxxxf0)(xf.2,1,1xxx【解】令,则令,得,8)2(,13)1(,19)1(afafaf,0)2(,0)1(,0)1(fff.813a.utxxxxduuufduufxduufux000)()()()(【解】（令)xdttxtfxF0)()(kxxxkxbxxduuufduufxbxxxF00202021)()(lim21)(lim100)()()(limkxxbkxxxxfxxfduuf20)1(1)(limkxxkbkxf20)1ln()(limxxxxfx2))(2()(lim2220xxxxxxfx由0x1y0ee11yyyxy10xy【解】令得.0)1(e1yyyy.0e)2(12yyyyy,cos)sin(lnddxyyxyfxz.0dd0xxz,sin)()sin(lncos)sin(lndd22222xyyyyxyfxyyxyfxz1)12)(0(dd022fxzx.20xy【解】0|)6()0(,2|)23()0(002tttxtxtyuut10de2t,1e)0(y;2)0(2ey等式两端对求导可得,210edxdyt2edd2022txy则utx2duufxduufxxxxxxsin02sin0222)(1)(1)()0(x.0)0(【解】令，则由已知得0xxxxxxxxxfxduufxxsin022232)cossin2()sin(1)(2)(xxxxxxxfduufxsin0232)cossin2)(sin()(2（1）当时，有xxx)0()(lim)0(0xxxduufxsin0302)(1lim)(sinlim320fxxxx.2)0(f.0,2;0),cossin2)(sin()(2)(sin0232xxxxxxxfduufxxxxxxxxxxxxxfduufxxsin023...