急急急!一道数学题在棱长为1的正方体ABCD--A1B1C1D1中,E,F分别是DD1,DB的中点,G在棱长CD上,CG=1/4CD,H是C1G是中点.(1)求证EF垂直于B1C.(2)求EF与C1G所成的角的余弦值.(3)求FH的长.详细过程,谢谢!
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/30 03:08:18
![急急急!一道数学题在棱长为1的正方体ABCD--A1B1C1D1中,E,F分别是DD1,DB的中点,G在棱长CD上,CG=1/4CD,H是C1G是中点.(1)求证EF垂直于B1C.(2)求EF与C1G所成的角的余弦值.(3)求FH的长.详细过程,谢谢!](/uploads/image/z/3682333-37-3.jpg?t=%E6%80%A5%E6%80%A5%E6%80%A5%21%E4%B8%80%E9%81%93%E6%95%B0%E5%AD%A6%E9%A2%98%E5%9C%A8%E6%A3%B1%E9%95%BF%E4%B8%BA1%E7%9A%84%E6%AD%A3%E6%96%B9%E4%BD%93ABCD--A1B1C1D1%E4%B8%AD%2CE%2CF%E5%88%86%E5%88%AB%E6%98%AFDD1%2CDB%E7%9A%84%E4%B8%AD%E7%82%B9%2CG%E5%9C%A8%E6%A3%B1%E9%95%BFCD%E4%B8%8A%2CCG%3D1%2F4CD%2CH%E6%98%AFC1G%E6%98%AF%E4%B8%AD%E7%82%B9.%EF%BC%881%EF%BC%89%E6%B1%82%E8%AF%81EF%E5%9E%82%E7%9B%B4%E4%BA%8EB1C.%EF%BC%882%EF%BC%89%E6%B1%82EF%E4%B8%8EC1G%E6%89%80%E6%88%90%E7%9A%84%E8%A7%92%E7%9A%84%E4%BD%99%E5%BC%A6%E5%80%BC.%EF%BC%883%EF%BC%89%E6%B1%82FH%E7%9A%84%E9%95%BF.%E8%AF%A6%E7%BB%86%E8%BF%87%E7%A8%8B%2C%E8%B0%A2%E8%B0%A2%21)
xV[OG+$U*"m^{H}Yk^ 4'c0`BalH1Oov%nռTZd33}F*>r6X(2Y3^jz"~vP
ݺu[
>d$7A($p `OHÏ3 (8ʒ7t]U3Uu(L6[28t²^v)#q4
Tz`]y:i]L{9ϵ}ϓWqEC]rQ[ޖ~?d|5^G_bӘ%yR\X+; ,HfE}_ay"I_Pm4$w`lsWzyٶGgBY1@Xmc/9"0Ó)ĭTT]␃QB-D昑\Bx+3y"KOTA),GU=,˘vb @%²õqZۮd.3[q7-2QTRi'R*sF{fxf5ԒFb 9Ϭ8.3wGoPr1JJrǂF"M0McC"8US6RU`w,9Mro;EMAއxN##iQٚZ욁@AXFS;툉1Vr0kpw:>oR^^dq1v{@W(
g{A2x,&tŅD2)wG$ @Lp};
(EXX>ŸW]ЇOc~'bmh%Udm9