设\(z = xy{e^{\sin xy}}\)，则\({z'_y} = \)（ ）。 A: \(x{e^{\sin xy}}\left( {1 + xy\cos xy} \right)\) B: \(y{e^{\sin xy}}\left( {1 + xy\cos xy} \right)\) C: \(x{e^{\sin xy}}\left( {1 + y\cos xy} \right)\) D: \(x{e^{\sin xy}}\left( {1 - xy\cos xy} \right)\)

设u=cos(xy),则du=( ).? cos(xy)(ydx+xdy)|-sin(xy)(ydx+xdy)|sin(xy)(ydx+xdy)|-cos(xy)(ydx+xdy)

设\(z = {e^u}\sin v,\;u = xy,\;v = x + y\)，则\( { { \partial z} \over {\partial y}}=\)( ) A: \(x{e^{xy}}\sin \left( {x + y} \right) + {e^{xy}}\cos \left( {x + y} \right)\) B: \(x{e^{xy}}\sin \left( {x + y} \right) \) C: \( {e^{xy}}\cos \left( {x + y} \right)\) D: \(x{e^{xy}}\sin \left( {x + y} \right) - {e^{xy}}\cos \left( {x + y} \right)\)

<img src="http://edu-image.nosdn.127.net/E6A0628104FCB0F521FBF2AAAC7F1968.png?imageView&thumbnail=890x0&quality=100" style="width: 558px; height: 33px;" />? syms xy=log(1/x*x+exp(x))+sin(1-x^2)dy/dx=diff(y,x)|syms xy=log(1/x/x+exp(x))+sin(1-x^2)dydx=diff(y,x)|syms xy=log(1/x/x+exp(x))+sin(1-x)^2dydx=diff(y,x)|syms xy=log(1/x/x+exp^x)+sin(1-x^2)dydx=diff(y,x)

【单选题】求函数y=sin(xy)+x/5的极小值,初始点为(1,1)的命令为( )。 A. FindMinimum[Sin[x*y]+x/5,{x,1},{y,1}] B. FindMinimum[sin[xy]+x/5,{x,1},{y,1}] C. FindMaximum[Sin[x*y]+x/5,{x,1},{y,1}] D. Findminimum[Sin[x*y]+x/5,

设\(z = \int_ { { x^2}}^y { { e^t}\sin t} dt\)，则\({z''_{xy}} = \)______ 。

曲线sin（xy）＋ln（y－x）＝x在点（0，1）处的切线方程是____。

z= x 2 y 2 +sin(xy),则z对y的偏导为（）。

画出函数f(x,y)=sin(xy)在区域[img=138x23]1803072d305f022.png[/img]上的去网格线、去边界框三维图形。 A: Plot3D[Sin(x y),{x,-5,5},{y,-3,3}, Mesh®None, Boxed®False] B: Plot3D[Sin[xy],{x,-5,5},{y,-3,3}, Mesh®None] C: Plot3D[Sin[x y],{x,-5,5},{y,-3,3},Boxed®False, Mesh®None] D: Plot3D[Sin[x y],{x,-5,5},{y,-3,3},Boxed®False]

设随机变量服θ从&#91;-π，π&#93;上的均匀分布，令X=sinθ，Y=cosθ，则 (1) E(X)=1. (2)E(XY)=2. (3)ρXY=3.