设函数f(x)由方程e^y xy=e确定求y(0).
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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)
e^(xy)(y+xdy/dx)-4x-dy/dx=0;dy/dx(xe^(xy)-1)=-ye^(xy)+4x;dy/dx=(4x-ye^(xy))/(xe^(xy)-1).
1.(1)f'(x)=e^x+e^(-x)求导公式的运用,然后用基本不等式.所以f'(x)=e^x+e^(-x)≥2根号(e^x+e^(-x))≥2就是求导求好了然后用基本不等式.不然怎么证(2)因为
1)x=0代入方程:1-e^y=0,得y(0)=0两边对X求导:e^x-y'e^y=cos(xy)(y+xy')y'=[e^x-ycos(xy)]/[xcos(xy)+e^y]代入x=0,y(0)=0
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/
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+
两边对x求导:y'e^y+(1+y')cos(x+y)=0,1)这里可得到y'=-cos(x+y)/[e^y+cos(x+y)]再对1)求导:y"e^y+(y')^2e^y+y"cos(x+y)-(1
=-[ysin(xy)+2e^(2x+y)]/[ysin(xy)+e^(2x+y)]*(dx)再问:麻烦给我写出解的过程。。再答:等式两边取对数,得:d[e^(2x+y)]-d[cos(xy)]=0(
因为x、y都为自变量,不是宗量,故此题没有全微分,应只有偏微分.详解如下:对方程两边微分:左边:de^z=e^z*dz右边d[xyz+cos(xy)]=xydz+yzdx+xzdy-(sinxy)*(
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]
dz=-dx-dy
Fx=e^x-y^2Fy=cosy-2xydy/dx=-Fx/Fy=(y^2-e^x)/(cosy-2xy)
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'(
y'=(x)'e^y+x(e^y)'y'=e^y+xe^y*y'再问:x(e^y)'=xe^y*y'?再答:对,因为y是x的函数,根据复合函数求导法,可得
/>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'
两边对x求导:1+y'=y'e^y得dy/dx=y'=1/(e^y-1)