设(x,y)=sin xy,则(x,y)=sin xy

lim _(x arrow 2) (sin xy)/(y) = ( )A. $\infty$B. 0C. 1D. 2

设 z = e^u sin v，而 u = xy，v = x + y，则 (partial z)/(partial x) = ( )A. $z = e^{xy}

5.-|||-设(x)=dfrac (xy)(sin xy)+idfrac (x+y)(x+y+2), 则 lim _(xarrow 0)f(x)=1-|||-

设函数y=y(x)由方程e x-e y=sin(xy)所确定,求dy/dx|x=0设函数y=y(x)由方程e x-e y=sin(xy)所确定,

5【判断题】设f(x,y)=(xy)/(x^2)+y，则f(xy,(x)/(y))=(xy)/(xy^3)+1.A. 对B. 错

已知函数z=f(xy,sin x+sin y)，f具有连续的偏导数，则(partial z)/(partial x)=(）A. $xf_1' + \cos x

设y=sin x，则dy=____。填空题（共15题，30.0分）39. (2.0分) 设$y=\sin x$，则$dy=$____。

(6) ^2y+3xy=sin 2x 。

设 y=y(x) 是由 sin (xy)=ln dfrac (x+e)(y)+1 确定的隐函数,求y`(0)和 y``(0)的值.

[单选题]设y=sin2x，则y′等于().A.-cos2xB.cos2xC.-2cos2xD.2cos2x