(本小题满分12分)
已知四棱锥P-ABCD的底面是直角梯形,∠ABC=∠BCD=90°,E为BC中点,AE与BD交于O点,
AB=BC=2CD,PO⊥平面ABCD.
(1)求证:BD⊥PE;
(2)若AO=2PO,求二面角D-PE-B的余弦值.
推荐套卷
(本小题满分12分)
已知四棱锥P-ABCD的底面是直角梯形,∠ABC=∠BCD=90°,E为BC中点,AE与BD交于O点,
AB=BC=2CD,PO⊥平面ABCD.
(1)求证:BD⊥PE;
(2)若AO=2PO,求二面角D-PE-B的余弦值.