二、解答下列各题1.设=arctan dfrac (y)({x)^2}，求dz。

求下列复合函数的偏导数或导数:-|||-(1)设 =arctan (xy) ,y=e^x, 求 dz/dx;-|||-(2)设 =dfrac ({x)^2+(y

设(X,Y)的分布函数为(x,y)=dfrac (1)({pi )^2}(dfrac (pi )(2)+arctan dfrac (x)(2))(dfrac (

1.设 sin y+(e)^x-x(y)^2=0, 求 dfrac (dy)(dx).-|||-2.设 ln sqrt ({x)^2+(y)^2}=arctan

1、设z=arctan(x)/(y)，求dz|_(1,1).1、设$z=\arctan\frac{x}{y}$，求dz|_(1,1).

1.求下列复合函数的偏导数或导数:-|||-(1)设 =arctan (xy) ,y=e^x, 求 dfrac (dx)(dx)-|||-(2)设 =dfrac

[试题]设函数；=arctan(xy)+2x2+y，求dz.

6.求下列各函数的函数值:-|||-(1) (x,y)=([ dfrac {arctan (x+y))(arctan (x-y))] }^2 ,求 (dfrac

5.设 =arctan (xy), 而 =(e)^x, 求 dfrac (dz)(dx).

求下列初值问题的解：(dfrac (1+{x)^2}(2))y=arctan x，(dfrac (1+{x)^2}(2))y=arctan x.（ ）求下列初值

1.求下列极限.-|||-(4) lim _(xarrow +infty )dfrac (ln (1+dfrac {1)(x))}(dfrac {pi )(2)