A.绝对收敛
B.条件收敛
C.发散
D.
[单选题]A.绝对收敛B.条件收敛C.发散D.
[单选题]A.B.C.D.
[单选题]A.(x-2y)y′=2x-yB.(x-2y)y′=2xC.xy′=2x-yD.-2yy′=2x-y