共50条信息
如图,在四棱锥\(P-ABCD\)中,\(AD⊥\)平面\(PDC\),\(AD/\!/BC\),\(PD⊥PB\),\(AD=1\),\(BC=3\),\(CD=4\),\(PD=2\).
\((I)\)求异面直线\(AP\)与\(BC\)所成角的余弦值;
\((II)\)求证:\(PD⊥\)平面\(PBC\);
\((\)Ⅲ\()\)求直线\(AB\)与平面\(PBC\)所成角的正弦值\(.\)
点\(E,F\)分别是三棱锥\(P-ABC\)的棱\(AP,BC\)的中点,\(AB=6\),\(PC=8\),\(EF=5\),则异面直线\(AB\)与\(PC\)所成的角为
如图,圆锥的高\(PO=4\),底面半径\(OB=2\),\(D\)为\(PO\)的中点,\(E\)为母线\(PB\)的中点,\(F\)为底面圆周上一点,满足\(EF\bot DE\).
\((1)\)求异面直线\(EF\)与\(BD\)所成角的余弦值;
\((2)\)求二面角\(O-DF-E\)的正弦值.
如图,四棱锥\(P-ABCD\)的底面\(ABCD\)为一直角梯形,其中\(BA\bot AD,CD\bot AD\),\(CD=AD=2AB\),\(PA\bot \)底面\(ABCD\),\(E\)是\(PC\)的中点.
\((1)\)求证:\(BE/\!/\)平面\(PAD\);
\((2)\)若\(BE\bot \)平面\(PCD\),求异面直线\(PD\)与\(BC\)所成角的余弦值;
已知空间四边形\(ABCD\)中,\(E\)、\(F\)分别是\(BC\)和\(AD\)的中点,若\(BD\bot AC\),\(BD=AC\),则\(EF\)与\(BD\)所成角的大小是_______
如图,正四棱柱\(ABCD-{A}{{{"}}}{B}{{{"}}}{C}{{{"}}}{D}{{{"}}}\)中\((\)底面是正方形,侧棱垂直于底面\()\),\(A{A}{{{"}}}=3AB\),则异面直线\({A}{{{"}}}B\)与\(A{D}{{{"}}}\)所成角的余弦值为\((\) \()\)
已知正方体\(ABCD-{{A}_{1}}{{B}_{1}}{{C}_{1}}{{D}_{1}}\)中,\(E\)、\(F\)分别为\(BC\)、\(C{{C}_{1}}\)的中点,则异面直线\(EF\)与\(A{{C}_{1}}\)所成角的正弦值为__________.
如图,\(PA\bot \)平面\(ABC\),\(AC\bot AB\),\(AP=BC=4\),\(\angle ABC=30{}^\circ \),\(D\),\(E\)分别是\(BC\),\(AP\)的中点,求异面直线\(AB\)与\(ED\)所成角的大小为
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