设y=f(x)是由方程x y 确定的隐函数
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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)
方程两边微分就行了dx*y+x*dy+e^y*dy=2xdx得dy/dx=(2x-y)/(x+e^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
对方程两边求全微分得:(e^z-1)dz+y^3dx+3xy^2dy=0(方法和求导类似)移项,有dz=-(y^3dx+3xy^2dy)/(e^z-1)
(-2y^2)/(4xy+e^y)
两边对x求导有y'e^y=y+xy'整理解得y‘=dy/dx=x/(e^y-x)
e^z-z+xy^3=0偏z/偏x:z'e^z-z'+y^3=0y^3=z'(1-e^z)z'=y^3/(1-e^z)偏z/偏y:z'e^z-z'+3xy^2=0z'=3xy^2/(1-e^z)偏z/
直接两边对X求导,注意Y是X的函数.所以得:y+xy'=e^(x+y)*(1+y'),化简,代入原方程得:y+xy'=xy(1+y'),然后对得到的式子在此求导,得:y'+y'+xy''=(y+xy'
再答:隐函数高阶求导。再答:
e^(xy)+sin(xy)=y(y+xy')e^(xy)+(y+xy')cos(xy)=y'y'=(ye^(xy)+ycos(xy))/(1-xe^(xy)-xcos(xy))
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
等式xy+2lnx=y4两边直接对x求导,得y+xy′+2x=4y3y′将x=1,y=1代入上式,有 y'(1)=1 故过点(1,1)处的切线方程为y-1=1•(x-1),即x-y
y是x的函数,对x求导则e^(x²)*(x²)'-2y*y'=x'*y+x*y'2xe^(x²)-2y*y'=y+x*y'y'=[2xe^(x²)-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]
Fx=e^x-y^2Fy=cosy-2xydy/dx=-Fx/Fy=(y^2-e^x)/(cosy-2xy)
x=0时,代入方程得:1+1=y,得:y=2对x求导:(y+xy')e^xy-sin(xy)*(y+xy')=y'将x=0,y=2代入得:2=y'故dy(0)=2dx
(cos(x+y)-y)\(x-cos(x+y))