sin(x+y)+e^xy=4x,y'=

Z=x*sin xy+e^x+y或设y=(x)是由方程xy+sin x+sin y=1确定,求y” 设隐函数y=y(x)由方程x^y-e^y=sin(xy)所确定,求dy 设y=y(x)由方程e^xy+sin(xy)=y确定,求dy/dx. sin (x^2+y^2)+e^x-xy^2=0求dy e^x+e^y=sin(xy),求dy/dx.怎么求 设方程e^(x+y) + sin(xy) = 1 确定的隐函数为y=y(x),求y'和y'|x=0 多元函数极限lim sin(xy)/x (x.y) -> (0.2) = lim {[sin(xy) / xy ] * e^y+ln(xy)-e^(-x)=0,求y' （1）y-sin（Inx）求y （2）（e^x+y）-xy=0求dy 设函数y=f(x)由方程sin(xy)+e^(x+y)=0确定,求dy/dx E[(X-E(X))*(Y-E(Y))]=E(XY)-E(X)*E(Y)这个公式怎么证明? 求下列导数：sin(x+y)=sinx+siny e^x+x=e^y+y