• 2022-07-24
    设[img=114x25]1803d68421f181b.png[/img]为单连通区域[img=15x19]1803d6842a9ab92.png[/img]上有一阶连续偏导数的函数,方程[img=199x25]1803d68432d2fbf.png[/img]在区域[img=15x19]1803d6842a9ab92.png[/img]上为全微分方程,当且仅当在[img=15x19]1803d6842a9ab92.png[/img]内成立( ).
    A: [img=100x47]1803d6844ee4422.png[/img]
    B: [img=69x47]1803d6845762a86.png[/img]
    C: [img=69x47]1803d6845fdbd64.png[/img]
    D: [img=100x47]1803d684681e28b.png[/img]
  • 举一反三