如图,已知三棱柱ABCA1B1C1中,AB⊥AC,AB=2,AC=4,AA1=3,点D是BC的中点.
(1) 求直线DB1与平面A1C1D所成角的正弦值;
(2) 求二面角B1A1DC1的平面角的正弦值.
(1) (2)