摘要:侧棱PC⊥底面ABCD.且PC=2. ------7分设点C到平面PDB的距离为d.
网址:http://m.1010jiajiao.com/timu_id_185061[举报]
(1)证明:P为A1B中点.
(2)若A1B⊥AC1,求二面角B1-PC-B的余弦值. 查看习题详情和答案>>
(1)证明:P为A1B中点.
(2)若A1B⊥AC1,求二面角B1-PC-B的余弦值.
查看习题详情和答案>>
网址:http://m.1010jiajiao.com/timu_id_185061[举报]