(1 xy)的y次方全微分-搜答案-搜搜做题作业网

我来试试吧...z=e^xy*cos(x+y)Z'x=ye^xycos(x+y)-e^xysin(x+y)Z'y=xe^xycos(x+y)-e^xysin(x+y)故dZ=[ye^xycos(x+y

令u=2x^2-y^2,v=xy然后链导法则!再问：请您把详细过程给我好吗？再答：偏导数符号打不上去啊du=(4xfu+yfv)dx+(-2yfu+xfv)dy其中fu、fv是偏导数符号

z'x=2e^(2x+y)z'y=e^(2x+y)所以dz=2e^(2x+y)dx+e^(2x+y)dy

Z=e^xy在x处的导函数为ye^(xy)在y处的导函数为xe^(xy)dz=ye^(xy)dx+xe^(xy)dy=2e^2dx+e^2dy

y=2x+1第二题题目含糊

dz=[sin(xy)+xycosxy]dx+(x^2cosxy)dydz|(1,1)=(sin1+cos1)dx+cos1dy再问：先求dx，dy，详细过程谢谢再答：=sin(xy)+xycosxy

(y^2+2xy-cos(y+z))/(e^z+cos(y+z))再问：没有过程吗？再答：求导：e^z*dz-y^2-2xy+cos(y+z)(1+dz)=0把含有dz的项移到一起：(e^z+cos(

用对数求导法和隐函数求导法,先取对数,再用隐函数求导方法

解；z(x)=2x+2y²z(y)=4xy+12y²dz=(2x+2y²)dx+(4xy+12y²)dy

3、e^(xy)=2x+y^3,两边取微分d[e^(xy)]=d[2x+y^3]ye^(xy)dx+xe^(xy)dy=2dx+3y^2dy[xe^(xy)-3y^2]dy=[2-ye^(xy)]dx

dz=[-3ysin3xy+1/(1+x+y)]dx+[-3xsin3xy+1/(1+x+y)]dy

...偏z/偏x=-8切线（x-8)/8=(y+8)/1=(z-8)/8,法平面：x+z-8=1(8):应该是抛物线y^8=8x吧抛物线在（8,8...函数z=In(x+y)沿着这抛物现在该点处偏向x

再问：非常感谢，还要问大侠一道题面目。曲线y=x³+3x的拐点坐标为？？？再答：y'=3x²+3y''=3x令y"=0，得x=3当x=3时，y=36所以拐点坐标（3，36）

两边即对数得：lnz=xy*ln(lnu),不妨记u=x^2+y^2z'x/z=yln(lnu)+2x^2y/lnu,z'x=z[yln(lnu)+2x^2y/lnu]z'y/z=xln(lnu)+2

xy-e^x+e^y=0d(xy-e^x+e^y)/dx=0d(xy)dx=y*dx/dx+x*dy/dx=y+xdy/dxd(e^x)/dx=e^x*dy/dxd(e^y)/dx=e^y*dy/dx

az/ax=y^3-2xy^6az/ay=3xy^2-6x^2y^5所以dz=(y^3-2xy^6)dx+(3xy^2-6x^2y^5)dy在点(1,1)的全微分为dz=-dx-3dy

求二元函数全微分z=f[x²-y²,e^(xy)]设z=f(u,v),u=x²-y²,v=e^(xy)则dz=(∂f/∂u)du+(&#

[xy+y²]'=[e^x]'-->y+xy'+2yy'=e^x-->y'[x+2y]=e^x-yy'=[e^x-y]/[x+2y]dy={[e^x-y]/[x+2y]}dx

dz=(y+1/y)dx+(x-x/y^2)dy

再问：就是这个吗？再答：是的。如还有不懂请追问，懂了请采纳。再问：还有这三题