z=f(x,y)=x^3 + x^2 * y + x^2 ln(2+y)+e^(x+5) *y 求导数 dz/dx

分解因式:f(x,y,z)=x^2(y-z)+y^2(z-x)+z^2(x-y) 一道函数不等式题求出所有这样的函数f:R-R,使得对于一切x,y,z∈R,有f(x+y)+f（y+z）+f(x+z)=3f(x+2y+3z)f(x+y)+f（y+z）+f(x+z)=3f(x+2y+3z)改为f(x+y)+f（y+z）+f(x+z)≥3f(x+2y+3z) f(x,y,z)=(x^2+y^2)^0.5+z^1.5,求 ∂f(x,y,z)/∂y 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 设z=f(x^2-y^2,e^（xy)),求偏导z/x,偏导z/y 设f(x,y,z)=e^x*y*z^2,其中z=z(x,y)是由x+y=z+x*e^(z-x-y)确定的隐函数,则f'x(0,1,1)= 设函数f可微,z=f(ye^x,x/(y^2)) 求z/x,z/y 证明 ：x/(y+z)+y/(z+x)+z/(x+y)>=3/2其中 x,y,z>0 x/2=y/3=z/5 x+3y-z/x-3y+z x+y/2=z+x/3=y+z/4 x+y+z=27 若x+y+z=3y=2z,则x/x+y+z=? x+2y=3x+2z=4y+z 求x:y:z 求f(x,y,z)=2x+y+3z在椭圆x^2+y^2=2,x+z=1的最大最小值 Matlab的高手来帮小弟个忙,给这个程序每句加个注释.感激不尽啊!Syms x y z; % f=x^2+y^2+z^2; n=jacobian(f,[x,y,z]); % [X,Y,Z]=sphere;U=subs(n(1),{x,y,z},{X,Y,Z});V=subs(n(2),{x,y,z},{X,Y,Z});W=subs(n(3),{x,y,z},{X,Y,Z});quiver3(X, 设z=f(x^2,y,y/x)可导,求δz/δx,δz/δy f(x,y,z,w)=x*(x+y)*(x+y+z)*(x+y+z+w)f=x+1, u=x+2, z=x+3, c=x+5, v=x+6, k=x+7, l=x+8求f(f,u,c,k) 设z=f(x,y)满足x²+2y²+3z²+xy-z-9=0,求z对x的二阶偏导数.