设G为圆域x(来学网)+y≤4,则下列式子中正确的是:
  • A.
    (来学网)sin(x+y)dxdy=sin4dxdy
  • B.
    (来学网)sin(x+y)dxdy=sinrdr
  • C.
    (来学网)sin(x+y)dxdy=rsinrdr
  • D.
    (来学网)sin(x+y)dxdy=sinrdr