2019꽭ʡ̩пѧԾ ʱ120ӣ150֣
ע⣺1.Ծѡͷѡ֣
2.Ĵ𰸾дڴϣдԾЧ 3.ͼ2BǦʣӺڼӴ֡
һ ѡ⣨18֣
һѡ⣨6С⣬ÿС3֣18֣ÿСĸѡУǡһǷĿҪģѡȷѡĸͿڴӦλϣ 11෴ǣ A1
B1
C0
D1
2ͼеԳͼǣ
32x2+6x1=0Ϊx1x2x1+x2ڣ
A6 B6 C3 D 3 4СͬѧʵؾȵӲ顱õ±
ӲҵĴΪ1000泯ϡƵӽ A200
B300
C500
D800
5BCDEFGСεĶϣͼʾɱ߳ͬСɣAABCǣ AD CF
DG BE
62a3b=1ʽ4a26ab+3bֵΪ A1
B1 C2
1
D3
ڶ ѡ⣨132֣
⣨10С⣬ÿС3֣30.ѴֱдڴӦλ. 7㣺У10
8ʽ
92019528գҹѧԶƿԼΪ11000mɺϲ˽10Ƭɺ֣11000ÿѧʾΪ
10ʽ
1壬xȡֵΧ
2x?1?x?1Ľ⼯Ϊ ??y??311˱εڽǺΪ
12⡰εڽǡ ⡱⡱
13ij̳2018ĸȵӪҵƳͼʾͳͼжȵӪҵΪ1000Ԫ̳ȫӪҵΪ Ԫ
14xķx2+2x+m0ȵʵmȡֵΧ
15ͼֱε3ΪԲģ߳Ϊ뾶λΧɵͼγΪ.α߳Ϊ6cmεܳΪ cm
16ͼOİ뾶Ϊ5PڡOϣAڡOڣAP3,AAPĴ߽ڡOBC.PB=x,PC=y,yxĺʽΪ
⣨10С⣬102֣ڴָ𣬽ʱӦдҪ˵֤̻㲽裩
1712֣1㣺8
2
2x?53x?312 ̣ⷽ?3?6x?2x?22188֣
PM2.5ֱָСڻ2.5PMĿ彡ʹɲӰ.±Ǹݣȫп棩еIJͳƱ,ͳƱش: 2017ꡢ2018712ȫ338ϳƽŨͳƱ λpm/m2 · 7 2017 2018 27 23 24 24 30 25 38 36 51 49 65 53 8 9 10 11 12 12018712PM2.5ƽŨȵλΪ pm/m2; 2ͳͼ͡ͳͼУֱ۵طӳ2018712PM2.5ƽŨȱ仯̺Ƶͳͼ ;
3ijͬѧ۲ͳƱ˵20187122017ͬȣơһ仰˵ͬѧó۵ɡ
198֣
СѧУμӡҺҵûΪΣһСݳ 鷨չʾֶࡱ3ĿABCʾڶСݽʫС2ĿDEʾμԱÿθȡһĿ.û״ͼбķгСμĿеȿܵĽ,СǡóBDĿĸ.
208֣ͼ ABCУC=900 AC=4, BC=8, (1)ֱߺԲABĴֱƽ;(ͼۼ,Ҫд) (2)(1)Ĵֱƽ߽BCڵD,BDij.
3
A C 20ͼ B 2110֣ij̨ʾͼͼʾAC¶i=12Cˮƽ
0
ABĸ߶Ϊ10mӶDEǦ=1830䣬ֱCDľΪ
4mEAˮƽAFΪ3m 1ˮƽAB 2Eĸ߶EF.
(sin180300.32, tan180300.33,ȷ0.1m)
2210֣
ͼƽֱϵxoy УκͼĶΪ43ͼxཻڵAByཻڵCеA ĺΪ1. 1öκıʽ 2tanABC.
2310֣
СӪһˮ꣬ijյˮгһˮ.˽,һˮ
100kg300kgʱˮ۾Ϊ3Ԫ/kg.ͼ߱ʾyԪ/kgxkgĺϵ.
1ͼ߶ABֱߵĺʽ
2С800ԪһοˮǶ٣
4
y C O x A B