设函数y等于y(x)由方程x y

方程两边同时求x对y的导：y+xdy/dx+1/x+2ydy/dx=0,dy/dx=-(y+1/x)/(x+2y),dy=-(y+1/x)dx/(x+2y)

xy+e^y=y+1（1）求d^2y/dx^2在x=0处的值：（1）两边分别对x求导：y+xy'+e^yy'=y'y/y'+x+e^y=1(2)(2)两边对x再求导一次：(y'y'-yy'')/y'^

左右对x求导有y'/y=sec²(xy)(y+xy')整理有y'=y²/(cos(xy)-xy)所以dy=(y²/(cos(xy)-xy))dx

把x=0代入原方程得0+e^0+y=2∴y=1方程两边对x求导得：y+xy'+e^(xy)(y+xy')+y'=0移项、整理得：[x+xe^(xy)+1]y'=y+ye^(xy)∴y'=[y+ye^(

满意请采纳,谢谢

这个题目要利用隐函数的求导法则.则sin(x^2+y)=xy（两边同时求导,还要结合复合函数的求导法则）cos（x^2+y）*（2x+y′）=y+xy′2xcos（x^2+y）-y=xy′-y′cos

直接求导,用xy表示导数【欢迎追问,

（2）△Z=2.1×0.8-2×1dz=Zx·△x+Zy·△y=1×0.1+2×（-02）第一题我在想先

网上有很多高数课后习题答案,你可以下载一个参考~e^y-e^x=xy两边求导,得e^y*y'-e^x=y+xy'(e^y-x)y'=(e^x+y)所以y'=(e^x+y)/(e^y-x)x=0时,原式

xy+y^2-2x=0y+xy'+2yy'-2=0(x+2y)y'=2-yy'=(2-y)/(x+2y)dy/dx=(2-y)/(x+2y)

对y^2－2xy＝7求微分,得2ydy-2(ydx+xdy)=0,∴（y-x)dy=ydx,∴dy/dx=y/(y-x).

两端对x求导数（把y看作x的函数）,则1-y'=e^(xy)*(1*y+x*y')y'[xe^(xy)+1]=1-ye^(xy)dy/dx=y'=[1-ye^(xy)]/[xe^(xy)+1]

xy+e^y=1e^y(0)=1y(0)=0xy'+y+e^yy'=00+y(0)+y'(0)=0y'(0)=0xy''+y'+y'+e^yy''+(y')^2e^y=00+2y'(0)+y''(0)

x^2+xy+y^2=42x+y+y'x+2yy'=0y'=-(2x+y)/(x+2y)在点（2,-2）处的切线斜率=1切线方程为：y+2=x-2,即x-y-4=0

e^y-e^x=xy两边求导,得e^y*y'-e^x=y+xy'(e^y-x)y'=(e^x+y)所以y'=(e^x+y)/(e^y-x)x=0时,e^y-e^0=0,则e^y=1,则y=0所以y'(

（cos（x+y）-y）\(x-cos(x+y))

两边对x求导数,得y'*e^y+y+xy'=0,在原方程中令x=0可得y=1,因此,将x=0,y=1代入上式可得y'+1=0,即y'(0)=-1.再问：对x求导时y可以当成一个常数吗？为什么要用公式（

/>e^y+xy+e^x=0两边同时对x求导得：e^y·y'+y+xy'+e^x=0得y'=-(y+e^x)/(x+e^y)y''=-[(y'+e^x)(x+e^y)-(y+e^x)(1+e^y·y'

在方程ex+y+cos（xy）=0左右两边同时对x求导，得：ex+y（1+y′）-sin（xy）•（y+xy′）=0，化简求得：y′＝dydx＝ysin(xy)−ex+yex+y−xsin(xy)．

化为：e^(ylnx)-e^y=sin(xy)两边对x求导：e^(ylnx)(y'lnx+y/x)-y'e^y=cos(xy)(y+xy')y'[lnxe^(ylnx)-e^y-xcos(xy)]=[