xy=e^(x+y)
两边求导:
y + xy ′ = e^(x+y) * (1+y ′)
y + xy ′ = e^(x+y) + e^(x+y) * y ′
xy ′ - e^(x+y) * y ′ = e^(x+y) - y
y ′ = {e^(x+y) - y} / { x - e^(x+y) }
=================================
xy=e^x+y
两边求导:
y + xy ′ = e^x + y ′
xy ′ - y ′ = e^x - y
y ′ = ( e^x - y ) / (x-1)