【正文】
?????,)1( 2??? kxkk,!)( ky k ? .0)1( ??ky????????? ?knknxnkkk nk,0,)1()1( ?階導(dǎo)數(shù)求任意 ? ? )5(5x例: !5? ? ? )13(11x 0?例 . .c o ss i n 階導(dǎo)數(shù)的和求 nxyxy ??解 xx c o s)( s i n ??)2c o s ()( s i n ????? xx類似地可得 ?,2,1,2πcos)(cos )( ??????? ??? nnxx n)2s in ( ??? x)22s i n ( ???? x)22c o s ()( s i n ??????? xx )23s i n ( ???? x ??? ? ?3,2,1)2s i n(s i n )( ???? nnxx n ?? ?? ?? ? ,2s i ns i n ?????? ???? ?nbaxabax nn? ?? ?? ? .2c o sc o s ?????? ???? ?nbaxabax nn推廣).n,431,n 階導(dǎo)數(shù)寫出通常分析結(jié)果的規(guī)律性合并不要急于階后或求出階導(dǎo)數(shù)時求 ?的各階導(dǎo)數(shù)。 167。前面的求導(dǎo)法則和導(dǎo)數(shù)).0(),0(,a rc t a n . ffxy ?????? 求設(shè)例,21 1 xy ??? )1 1( 2 ????? xy ,22 )1( 2xx???))1( 2( 22 ??????? xxy 322)1()13(2xx???022 )1(2)0(???????xxxf0322)1()13(2)0(???????xxxf。()()]()([)1(