(来学网)微分方程y″+y=3sinx+4cosx的特解形式应设为:
  • A.
    (来学网)Acosx+Bsinx
  • B.
    (来学网)x(Acosx+Bsinx)
  • C.
    x(来学网)(Acosx+Bsinx)
  • D.
    (Ax(来学网)+B)sinx+Cxcosx