第1826题：隐函数的导数
求由方程 xy=ex−yxy=\mathrm{e}^{x-y}xy=ex−y 确定的隐函数的导数.
A. dydx=ex−y−y−ex−y+x\dfrac{dy}{dx}=\dfrac{\mathrm{e}^{x-y} -y}{-\mathrm{e}^{x-y}+x}dxdy=−ex−y+xex−y−y
B. dydx=ex−y−yex−y+x\dfrac{dy}{dx}=\dfrac{\mathrm{e}^{x-y} -y}{\mathrm{e}^{x-y}+x}dxdy=ex−y+xex−y−y
C.dydx=ex−y−xex−y+y \dfrac{dy}{dx}=\dfrac{\mathrm{e}^{x-y} -x}{\mathrm{e}^{x-y}+y}dxdy=ex−y+yex−y−x
D. dydx=ex−y−x−ex−y+y\dfrac{dy}{dx}=\dfrac{\mathrm{e}^{x-y} -x}{-\mathrm{e}^{x-y}+y}dxdy=−ex−y+yex−y−x
