某间接测量量的测量公式为：$f = x + y - 2z$，则间接测量量f的不确定度合成公式，推导过程正确的是（） A $\frac{\partial f}{\partial x} = 0$ $\frac{\partial f}{\partial y} = 1$ $\frac{\partial f}{\partial z} = -2$ B $\frac{\partial f}{\partial x} = 1$ $\frac{\partial f}{\partial y} = 1$ $\frac{\partial f}{\partial z} = -1$ C $\frac{\partial f}{\partial x} = 1$ $\frac{\partial f}{\partial y} = 0$ $\frac{\partial f}{\partial z} = -2$ D $\frac{\partial f}{\partial x} = 1$ $\frac{\partial f}{\partial y} = 1$ $\frac{\partial f}{\partial z} = -2$
若z=f(x,y),x=u+v,y=u-v,则(partial^2z)/(partial upartial v)=(partial^2z)/(partial x
设 z = f(-(x)/(y))，且 f(x) 可导，则 (partial z)/(partial x) = ( )A. $f'\left(-\frac{x}
143.设由方程F(x,y,z)=0所确定的函数关系中，已知(partial F)/(partial x)=ye^z-e^y，(partial F)/(part
设f(u)可导，z=xyf((y)/(x))，若x(partial z)/(partial x)+y(partial z)/(partial y)=xy(lny
设 =f(xy,(x)^2+(y)^2), 其中 f 可微,则 dfrac (partial z)(partial x)= __
间接测量量N=x-2y，式中x、y为直接测量量，且x=(12.06±0.03)cm，y=(1.08±0.04)cm，则N的不确定度为（ ）cm间接测量量N=x-
[题目]设函数f w)具有二阶连续导数, =f((e)^xcos y)-|||-满足 dfrac ({partial )^2z}(partial {x)^2}+
设F(x, y, z)= 0定义z为x和y的隐函数，则(partial z)/(partial x)等于（） 设$F(x, y, z)= 0$定义$z$为$x
2.设z=f(xy,(y)/(x))，其中f具有二阶连续偏导数，则(partial^2z)/(partial xpartial y)=（）.A. $f_{1}^
(B.)(partial f(x,y))/(partial x)连续，f(x,y)不可微. (C.)(partial f(x,y))/(partial x)不连