已知xy+e^y=e...求dx/dy|x=0
问题描述：
已知xy+e^y=e...求dx/dy|x=0
答
x = 0 ,e^y = e ,y = 1
xy + e^y = e
y + xdy/dx + e^ydy/dx = 0
dy/dx = -y / (x + e^y)
dx/dy|x=0 = -1 / e