设有平面闭区域D={(x,y)|-α≤x≤α,x≤y≤α),D1={(x,y)|0≤x≤α,x≤y≤α),则∫∫D(xy+cosxsiny)dxdy=()
A.2∫∫D1cosxsinydzdy B.2∫∫D1xydxdy C.∫∫D1(xy+cosxsiny)dxdy正确答案A
设有平面闭区域D={(x,y)|-α≤x≤α,x≤y≤α),D1={(x,y)|0≤x≤α,x≤y≤α),则∫∫D(xy+cosxsiny)dxdy=()
A.2∫∫D1cosxsinydzdy B.2∫∫D1xydxdy C.∫∫D1(xy+cosxsiny)dxdy正确答案A