һѡ
1.()ABCDĵ(-10)(02)(43)(31)ıABCDΪ( )
A. B.
C. D.ƽı
2.()֪ABCУ =a =ba·b<0SABC= ,|a|=3,|b|=5,abļн( )
A.30° B.-150° C.150° D.30°150°
3.()κy=x2ͼaƽƺõͼһκy=2x-5ͼֻһ(31)a=_________.
4.()ABC͵RtABDйĵױABڵƽ60°ǣAB=16 cm,AC=17 cm,CD=_________.
5.()ͼڡABCУ =a =b =c, =a,(0<<1), =b(0<<1),abʾc.
6.()ABCA1B1C1ĵ߳Ϊa,ⳤΪ a.
(1)ʵϵдABA1C1;
(2)AC1ABB1A1ɵĽ.
7.()֪M(-10)N(10)ҵPʹ ɹСĵȲ.
(1)PĹ켣ʲô?
(2)PΪ(x0,y0),QΪ ļнǣtan.
8.()֪EFGHֱǿռıABCDıABBCCDDAĪе.
(1)֤EFGHĵ㹲;
(2)֤BDƽEFGH;
(3)MEGFHĽ㣬֤ԿռһO .
ο
ѵų
⣺(1)MΪxM= D ıΪ2.
xD= (3)ABC ļнǣ =(68) =(2-5).
ѵѵ
һ1. =(12) =(12) = ߶AB߶DC㣬ABDC|AB|=|DC|ABCDƽıΣ| |= =(53)| |= | || },ABCDΣ; =(41)
1·4+2·1=60, ֱ ABCDҲǾΣѡD.
𰸣D
2. ·3·5sinsin= ,=30°=150°.
֡a·b<0,=150°.
𰸣C
3.(2,0) 4.13 cm
5.⣺ ߣ =m =m( - )=m(b-a),
= + =a+m(b-a)=(1-m)a+mb
ߣ =n =n( - )=n(a-b),
= + =b+n(a-b)=na+(1-n)b
ɢ٢ڣ(1-m)a+mb=na+(1-n)b.
abߣ
ⷽ۵ãm= ʽc=(1-m)a+mb= [(1-)a+(1-)b].
6.⣺(1)ԵAΪԭOABֱΪOyᣬAA1ֱΪOzᣬԾԭƽABB1A1ֱֱΪOxᣬռֱϵ.
֪A(000)B(0a,0),A1(0,0, a),C1(- a).
(2)ȡA1B1еMM(0 a)AMMC1 =(- a,0,0),
=(0a,0), =(0,0 a)
· =0 · =0MC1ABB1A1AC1AMɵĽǾAC1ABB1A1ɵĽ.
= ɵĽǣAC1ABB1A1ɵĽΪ30°.
7.⣺(1)P(x,y),M(-10)N(10)ã =- =(-1-x,-y), =(1-x,-y), =- =(2,0), · =2(1+x), · =x2+y2-1, =2(1-x).ǣ ǹСĵȲУȼ
ԣPĹ켣ԭΪԲģ Ϊ뾶ҰԲ.
(2)PΪ(x0,y0)
8.֤(1)BG ɹ֪EFGHĵ㹲棬( = )
(2)Ϊ .
EHBDEH EFGHBD EFGH
BDƽEFGH.
(3)OMOAOBOCODOEOG
(2)֪ ͬ EH FG,EGFHһMұMƽ֣
2017ɿ⣺2017˸߿ʷƾѧģ
2017ɿ2017˸߿ʱ/
