如图,四棱锥P-ABCD中,底面ABCD为矩形,侧面PAD为正三角形,且平面PAD⊥平面ABCD,E为PD中点...
问题详情:如图,四棱锥P-ABCD中,底面ABCD为矩形,侧面PAD为正三角形,且平面PAD⊥平面ABCD,E为PD中点,AD=2.(1)求*:平面AEC⊥平面PCD;(2)若二面角A-PC-E的平面角大小θ满足,求四棱锥P-ABCD的体积. ...
问题详情:如图,四棱锥P-ABCD中,底面ABCD为矩形,侧面PAD为正三角形,且平面PAD⊥平面ABCD,E为PD中点,AD=2.(1)求*:平面AEC⊥平面PCD;(2)若二面角A-PC-E的平面角大小θ满足,求四棱锥P-ABCD的体积. ...
问题详情:如图所示,已知AD∥BC,∠ABC=90°,AB=8,AD=3,BC=4,点P为AB边上一动点,若△PAD与△PBC相似,则AP= .【回答】4解析由AD∥BC,∠ABC=90°,易得∠PAD=∠PBC=90°,又由AB=8,AD=3,BC=4,设AP的长为x,则BP长为8﹣x,然后分别从△APD∽△BPC与...
问题详情:如图,在四棱锥P﹣ABCD中,侧面PAD是正三角形,且与底面ABCD垂直,底面ABCD是边长为2的菱形,∠BAD=60°,N是PB的中点,过A、D、N三点的平面交PC于M,E为AD的中点,求*:(1)EN∥平面PDC;(2)BC⊥平面PEB;(3)平面PBC⊥平面ADMN.【回答】解:(1)∵A...
Inthisarticle,bondingpaddesign,stencildesignandassemblyprocessofQFNdevicewillbeintroducedindetail.Thebondingpadofthecircuitboardisprovidedwiththegap,thegapandthepositioningholearespacedbycertaininterv...
问题详情:已知定点A(3,4),点P为抛物线y2=4x上一动点,点P到直线x=-1距离为d,则|PA|+d的最小值为( )A. B.2 C. D.【回答】A知识点:圆锥曲线与方程题型:选择题...
Whentypingonakeyboard,shouldbethewristpad,avoidwiththeforearmraised.Ensurethattheactivityisageappropriateandprovideprotectiveequipmentsuchashelmets,wristpads,andkneepads....
Thereportersreportedthatthelaunchpadwasonfireafterthelaunch.Themilitaryhasnotbeenabletodeterminetheexactlocationofthelaunchpad.Therocketexplodedonthelaunchpad,burningaliveandasphyxiatingengineers,desi...
问题详情:如图,在四棱锥中,O为AC与BD的交点,平面PAD,是正三角形,,. (1)若点E为棱PA上靠A近的三等分点,*:直线平面PBC; (2)求*:平面平面PDC. 【回答】*: (1)因为,,所以.……………2分点E为棱PA上靠A近的三等...
问题详情:如图,四棱锥P-ABCD中,侧面PAD是边长为2的等边三角形且垂直于底,是的中点.(1)*:直线平面;(2)点在棱上,且直线与底面所成角为,求二面角的余弦值.【回答】(1)见解析;(2)【详解】试题分析:(1)取的中点,连结,,由题意*得∥,利用线面平行的判...
问题详情:如图,P为平行四边形ABCD所在平面外的一点,过BC的平面与平面PAD交于EF,则四边形EFBC是()A.空间四边形 B.平行四边形C.梯形 ...
telephonenumBerswrittenonapadShewroteonapadofpaper.NexttoPaulsen,NimGoldmandoodledthoughtfullyonapad.Heputonapadofgauzeandastripofadhesivetapeoverthewound.Mobilehomeortrailersmaybeonapadwhichyourentin...
问题详情:如图,四棱锥P-ABCD中,侧面PAD为等比三角形且垂直于底面ABCD,E是PD的中点.(1)*:直线平面PAB(2)点M在棱PC上,且直线BM与底面ABCD所成锐角为,求二面角M-AB-D的余弦值 【回答】【解析】(1)令中点为,连结,,.∵,为,中点,∴为的中位线,...
问题详情:如图,在四棱锥P-ABCD中,侧面PAD为正三角形,底面ABCD为正方形,侧面PAD⊥底面ABCD,M为底面ABCD内的一个动点,且满足MP=MC,则点M在正方形ABCD内的轨迹为( ) A....
fixingofshoulderpadThepadisimpregnatedwithinsecticide.Neverpadoutyouressaywithirrelevantdetails.Startbynotbuyingyourselfasketchpad.Sheseesthestamppadonmysweater.Amongthosewhohandledahottherapeuticpad,...
问题详情:小明喜欢利用pad听歌,根据声音的(选填“音调”、“响度”或“音*”)就判断出是哪位歌手;音量太大会使耳膜受损,说明声能传递 (“信息”或“能量”),为此需要减小声音的 (“音调”、“响度”或“音*”).【回答】【分析...
问题详情:如图,在四棱锥P﹣ABCD中,底面ABCD是边长为2的正方形,侧面PAD⊥底面ABCD,且PA=PD=AD,E、F分别为PC、BD的中点.(Ⅰ)求*:EF∥平面PAD;(Ⅱ)求*:面PAB⊥平面PDC;(Ⅲ)在线段AB上是否存在点G,使得二面角C﹣PD﹣G的余弦值为?说明理由.【回答】...
Then,onesteamingAugustnightbetweenmortarattacks,thechaplainaskedforavolunteertodrivehimtothehelicopterpadthefollowingweekend.ThereisahelicopterpadrightinfrontofthesideofthePentagon.Thewingtouchedthere...
LateMondayafternoon,readingtheobscureandintricatemarkings,theyidentifiedalaunchingpad.Thecenterpiecewasanornatemodelrocketonagreenfaunalaunchingpad.UponreturningtoEngland,heemployedthefavorablemediaat...
Scrubeachopticalsurfacewithagauzepadsoakedinacetone.Ihadtopayrushshippingformybirthkit—allthesterilizedgauzepads,alcoholswabs,glovesandgoopthemidwifeneedsatthebirth.Firstaidkit.Itshouldhavelatexglove...
问题详情:如图,平面PAD⊥平面ABCD,四边形ABCD为正方形,∠PAD=90°,且PA=AD=2,E,F分别是线段PA,CD的中点,则异面直线EF与BD所成角的余弦值为.【回答】 知识点:三角函数题型:填空题...
问题详情: 如图,在四棱锥P-ABCD中,侧面PAD为正三角形,底面ABCD为正方形,侧面PAD⊥底面ABCD,M为底面ABCD内的一个动点,且满足MP=MC,则点M在正方形ABCD内的轨迹为( )A. B. C. D.【回答】A【解析】试...
CleaningProductSeriesisincludingspecialscouringpad,spongescouringpadandmultifunctionalscrubbrush.Roundsupplyofnylonabrasivepolishingabrasives,includinggrindingwheels,wingstoflyround,grindingdiscs,grin...
问题详情:.如图,四棱锥P-ABCD中,侧面PAD为等边三角形且垂直于底面ABCD,AB=BC=AD,∠BAD=∠ABC=90°,E是PD的中点.(1)*:直线CE∥平面PAB;(2)点M在棱PC上,且直线BM与底面ABCD所成角为45°,求二面角M-AB-D的余弦值.【回答...
Shesmasheditusingthephone'sspecial'SWYPE'keypad,whichenablesuserstoinputtextwithouttheirfingertipleavingthescreen.Inwordprocessing,aseparatesetofkeysnumbered0through9onawordprocessor'skeyboardthat...
问题详情:如图,四棱锥P-ABCD中,侧面PAD为等边三角形且垂直于底面ABCD,AB=BC=AD,∠BAD=∠ABC=90°。(1) *:直线BC∥平面PAD;(2) 若△PAD面积为2,求四棱锥P-ABCD的体积。【回答】(1)*:∵底面中,∴又平面,平面,∴...