A.sint²                           B.cosx²                                C.2xcosx²                    D.sinx²

29. 广义积分 (        )

A.-2                              B.2                               C.0                               D. 发散

30. 下列广义积分中发散的是 (         )

A.                 B.                C.                 D.

31. 下列级数中，收敛的是 (         )

A.                                                 B.

C.                                        D.

32. 下列级数中，条件收敛的是 (         )

A.                                          B.

C.                                        D.