A.C1y1+C2y2+y3 B.C1y1+C2y2-(C1+C3)y3 C.C1y1+C2y2-(1-C1-C2)y3 D.C1y1+C2y2+(1-C1-C2)y3
A.1 B.2 C.3 D.4
A.π2/4 B.π/2 C.π2/4+1 D.π/2+1
A.2 B.1 C.0 D.4
A.-16sin2t·cos2tdt B.-16sin2t·cos2tdt C.16sin2t·cos2tdt D.16sin2t·cos2tdt
A.-36 B.12 C.36 D.以上都不对
A.0 B.1 C.2π D.π