难点3_运用向量法解题.txt

3 . ()abca(51)b(17)c(12)(1)bc am(2)cabad(3)cosabc. 1abcda1b1c1d1檩abcdc1cb=c1cd=bcd. (1)c1cbd. (2) embed equation.3 a1cc1bd. 弸. 弸. . ab embed equation.3 ab=0. (1) embed equation.3 =a, embed equation.3 =b, embed equation.3 =c,|a|=|b| embed equation.3 embed equation.3 embed equation.3 embed equation.3 =ab embed equation.3 =c(ab)=cacb=|c|a|cos|c|b|cos=0,c1cbd. (2)a1cc1bda1cbda1cdc1 embed equation.3 =(a+b+c)(ac)=|a|2+abbc|c|2=|a|2|c|2+|b|a|cos|b|c|cos=0, |a|=|c|a1cdc1|a|=|c|a1cbd embed equation.3 =1a1cc1bd. 2abca1b1c1abcca=cb=1bca=90aa1=2mna1b1a1a. (1) embed equation.3 (2)cos (3)a1bc1m. 弸. . oxyz,. . xoyabc. (1)coxyz. b(010)n(101) | embed equation.3 |= embed equation.3 . (2)a1(102)c(000)b1(012). embed equation.3 = embed equation.3 =(012) embed equation.3 =10+(1)1+22=3 | embed equation.3 |= embed equation.3 embed equation.3 embed equation.3 (3)c1(002)m( embed equation.3 ) embed equation.3 embed equation.3 a1bc1m. 1.任. 2. 3.弸 (1) (2) (3) (4) 1.()abcd(10)(02)(43)(31)abcd( ) a. b. c. d. 2.()abc embed equation.3 =a embed equation.3 =bab0sabc= embed equation.3 ,|a|=3,|b|=5,ab( ) a.30 b.150 c.150 d.30150 3.()y=x2ay=2x5(31)a=_. 4.()abcrtabdab60ab=16 cm,ac=17 cm,cd=_. 5.()abc embed equation.3 =a embed equation.3 =b embed equation.3 =c, embed equation.3 =a,(01), embed equation.3 =b(01),abc. 6.()abca1b1c1a, embed equation.3 a. (1)aba1c1 (2)ac1abb1a1. 7.()m(10)n(10)p embed equation.3 . (1)p (2)p(x0,y0),q embed equation.3 embed equation.3 tan. 8.()efghabcdabbccdda. (1)efgh棻 (2)bdefgh (3)megfho embed equation.3 . (1)mxm= embed equation.3 embed equation.3 embed equation.3 d embed equation.3 2. xd= embed equation.3 embed equation.3 (3)abc embed equation.3 embed equation.3 embed equation.3 =(68 embed equation.3 =(25. embed equation.3 1. embed equation.3 =(12 embed equation.3 =(12 embed equation.3 = embed equation.3 embed equation.3 embed equation.3 abdcabdc|ab|=|dc|abcd| embed equation.3 |= embed equation.3 embed equation.3 =(53| embed equation.3 |= embed equation.3 | embed equation.3 | embed equation.3 ,abcd embed equation.3 =(41 14+21=60, embed equation.3 embed equation.3 abcdd. d 2. embed equation.3 35sinsin= embed equation.3 ,=30=150. ab0,=150. c 3.(2,0) 4.13 cm 5. embed equation.3 embed equation.3 embed equation.3 =m embed equation.3 =m( embed equation.3 embed equation.3 )=m(ba), embed equation.3 = embed equation.3 + embed equation.3 =a+m(ba)=(1m)a+mb embed equation.3 embed equation.3 embed equation.3 =n embed equation.3 =n( embed equation.3 embed equation.3 )=n(ab), embed equation.3 = embed equation.3 + embed equation.3 =b+n(ab)=na+(1n)b (1ma+mb=na+(1n)b. ab embed equation.3 m= embed equation.3 c=(1m)a+mb= embed equation.3 (1)a+(1)b. 6.(1)aoaboyaa1ozabb1a1ox. a(000b(0a,0,a1(0,0, embed equation.3 a),c1( embed equation.3 embed equation.3 a). (2)a1b1mm(0 embed equation.3 aammc1 embed equation.3 =( embed equation.3 a,0,0, embed equation.3 =(0a,0, embed equation.3 =(0,0 embed equation.3 a) embed equation.3 embed equation.3 =0 embed equation.3 embed equation.3 =0mc1abb1a1ac1amac1abb1a1. embed equation.3 = embed equation.3 embed equation.3 embed equation.3 embed equation.3 embed equation.3 ac1abb1a130. 7.(1)p(x,y,m(10n(10 embed equation.3 = embed equation.3 =(1x,y, embed equation.3 =(1x,y), embed equation.3 = embed equation.3 =(2,0), embed equation.3 embed equation.3 =2(1+x), embed equation.3 embed equation.3 =x2+y21, embed equation.3 =2(1x). embed equation.3 embed equation.3 p embed equation.3 . (2)p(x0,y0) embed equation.3 embed equation.3 8.(1bg embed equation.3 efgh棬( embed equation.3 embed equation.3 = embed equation.3 (2 embed equation.3 . ehbdeh embed equation.3 efghbd embed equation.3 efgh bdefgh. (3omoaobocodoeog (2 embed equation.3 embed equation.3 embed equation.3 eh embed pbrush fg,egfhmm embed equation.3