【正文】
4(31xxxxyxxxxxxyyxxxxxxyxxy???????????????????????????解:導(dǎo)數(shù)與微分 2111111))1( l n ()()()()()1l n (1)8)()()()()(:2tttar c t gttxtyxyar c t gtytxtxtyxyttyytxxtt??????????????????????????????(的函數(shù)的導(dǎo)數(shù):求下列參數(shù)方程給出例求導(dǎo)公式:由參數(shù)方程給出的函數(shù) ??導(dǎo)數(shù)與微分 1)0(111,001|c oss i ns i nc osc oss i ns i nc oss i nc os)()(0c oss i n)3(2)c os1(s i n)s i n()c os1()()()c os1()s i n()2(0???????????????????????????????????????????????????xyxyyxtyktttttetetetetetetxtyytteytextc t gtatattatatxtyytayttaxttttttttt切線方程為:時又=)()(=處的切線方程求在導(dǎo)數(shù)與微分 五、函數(shù)的微分 :設(shè)函數(shù) y=f(x)在點 x0處可導(dǎo) , 是自變量 x的增量 ,則稱 為函數(shù) f(x)在 x0處關(guān)于 ?x的微分 .記為 : ,即 : 定理 : 函數(shù) y=f(x)在 x點可微的充分必要條件是y=f(x)在 x點處可導(dǎo) . 即:函數(shù)可微 存在 ,則函數(shù)可導(dǎo)且 ,反之 ,函數(shù)可導(dǎo) ,既 存在 ,則 從而函數(shù)可微 . xxfdy ??? )( 0導(dǎo)數(shù)與微分 dxxfdxxxxxdxdyxyxxfdyxfy)(dy)(,)(),(????????????????寫成:數(shù)的微分的一般公式可變量的微分,從而函即自變量的增量等于自對于函數(shù)導(dǎo)數(shù)與微分 dxxxdyxxxxxyxln1ln1)( l nln1)ln( l nlnlny( 1)9??????????求下列函數(shù)的微分例導(dǎo)數(shù)與微分 dxaadyaaaatvaatvayttvvuayayxxxxxxxxxxxxuxuxu122122122212c o s21c o s21c o s11111212c o ss i nlns i nlnc oss i n2ln)()s i n(2ln)()( c os)()(,c os,:2)?????????????????????????????????令(導(dǎo)數(shù)與微分 dxx c t gyxy t gxydyx c t gyxy t gxyyy t gxyx c t gyxyyyyxyxxyxyyxxyyxxy???????????????????????c oslns i nlnc oslns i nlns i nln)c os( l nc oss i ns i nln)s i n(c osc oslns i nlnc osln)( s i n)( c os3)(導(dǎo)數(shù)與微分 ? x dxc s edc t gxx dxdt gxx dxxdx dxxddxxdaxdxxddxedeadxadadxnxdxdxxdxdcxaxxxxnn22111)11(s e c)10(s i nc os)9(c oss i n)8(ln)7(lnl og)6()5(ln)4()3()2(01??????????????????)(導(dǎo)數(shù)與微分 導(dǎo)公式對應(yīng)的記憶)。求導(dǎo)自變量對乘中間變量求導(dǎo)對中間變量即函數(shù)點處可導(dǎo),且在則點處可導(dǎo),在相應(yīng)的點處可導(dǎo),在若定理:設(shè)( x )xu( u )uy( x )( u )yx( x ) ]f[yu)(x)(),(),(??????????????ffufxxuufy導(dǎo)數(shù)與微分 注:復(fù)合函數(shù)求導(dǎo)法則的關(guān)鍵在于: ( 1) 將復(fù)合函數(shù)分解成若干個基本初等函數(shù); ( 2) 分別求出這些函數(shù)的導(dǎo)數(shù)并相乘; ( 3) 將所設(shè)中間變量還原 導(dǎo)數(shù)與微分 ? ?3 2223 2222134)4()(3121)(21,:,21)2(s e cs e c1)()( l n,ln:,ln( 1)4323131xxxuyxuyxuuyxyxc t gxxut gxuyt gxuuyt gxy????????????????????????????????令令求下列函數(shù)的導(dǎo)數(shù)例導(dǎo)數(shù)與微分 xxxxxxxxxt geeeeeevuevuyevvuuyey??????????????????c oss i n)s i n(1)()( c os)( l n,c os,ln:,c osln)3( 令導(dǎo)數(shù)與微分 ?1)1()1(2121111)()()( l n,ln:)1(,ln)4(2?????????????????????yxar c t gxxxvuxar c t gvuyxvar c t gvuuyyxar c t gy令求導(dǎo)數(shù)與微分 xxuxuxuxxxvvyvvuyy1c o s2111c o ss i n22ln)()s i n(2ln2)(( c o s)2(,c o s,2:25)121??????