ʱ : 中考第一轮复习第12讲《二次函数》专题训练含答案 - 百度文库ϿʼĶ
A2 B3 C4 D5
κͼƽ
3κy2x24x1ͼƽƵõy2x2ͼ( ) Aƽ1λƽ3λ Bƽ1λƽ3λ Cƽ1λƽ3λ Dƽ1λƽ3λ
ȽκĽʽ䷽ΪʽȻȷƽƣy2x24x12(x1)23úͼƽ1λƽ3λ͵õy2x2ͼ
𰸣C
ܽ κͼƽʵϾǶλõı任ȽκʽתΪʽȷ䶥꣬ȻաҼϼ¼Ĺɽв
ͨ3 κyx2ͼƽ1λƽ2λͼĺʽ( )
Ay(x1)22 By(x1)22
Cy(x1)22 Dy(x1)22 ġȷκĽʽ
4ͼıABCDΣD(03)ԵCΪy2
axbxcǡþxAB㣮
(1)ABCꣻ
(2)ABCߵĽʽ ⣺(1)ߵĶԳԿ֪AEBE. AODաBEC. OAEBEA.
εı߳Ϊ2mRtAODУ m2(3)2(2m)2m1. DC2OA1OB3.
ABCֱΪ(1,0)(3,0)(23)
(2)ⷨһߵĽʽΪya(x2)23A(1,0)a3.
5 ҳ 13 ҳ
ߵĽʽΪy3(x2)23.
ⷨߵĽʽΪyax2bxc֪߾A(1,0)B(3,0)C(23)㣬
abc0??
?9a3bc0??4a2bc3
a3
??
飬?b43
??c33.
ߵĽʽΪy3x243x33.
ܽ ôϵκʽ֪ѡʽ֪ͼ꣬һʽ֪κͼxĺ꣬轻ʽ֪߶Գ(С)ֵ趥ʽ
1
ͨ4 ֪yx2(6m2)xm3xAB㣬AB
2yԳƣ
(1)mֵ
(2)дߵĹϵʽ꣮ 塢κʵӦ 5ijһزԭֻڵۣԸز
1
ͶΪÿͶxԪɻP(x60)241(Ԫ)ڡʮ
100
塱滮мӿ쿪زۣ滮Ϊڹ滮ǰԸĿÿͶ100ԪͶʣʵʩ滮5ǰУÿ궼100Ԫв50Ԫһ·ɣͨǰزֻڵۣ·ͨ3Уزڱ
99
ۣҲۣ۵ͶΪÿͶxԪɻQ(100x)2
100
294(100x)160(Ԫ) 5
(1)п5ֵǶ٣
(2)滮ʵʩ5(۳·)ֵǶ٣ (3)(1)(2)÷Ƿʵʩֵ
⣺(1)x60ʱPΪ41Ԫֵ415205(Ԫ) (2)ǰ꣺0x50ʱΪPxx50ʱPֵΪ40ԪΪ40280(Ԫ)
꣺ÿΪyԪͶʶΪxԪͶʶΪ(100x)Ԫ
1992294?x60?241??xx160?x260x165(x30)21 yPQ?5?100??100?065x30ʱyΪ1 065ôΪ1 06533 195(Ԫ)ֵΪ803 1955023 175(Ԫ)
(3)мʵʩֵ
ܽ öκʽʵеֵСֵĿͣķǣ
1гκĹϵʽйϵʽʱҪԱʵ壬ȷԱȡֵΧ
2ԱȡֵΧڣùʽ䷽κֵСֵ ͨ5 һ߳ȥijߣɱΪ10Ԫ/Ϊ12Ԫ/
6 ҳ 13 ҳ
Ϊ2ƻͨʵӳɱ߲ƷΣչгÿijɱȥɱ0.7xÿij۱ȥӦ0.5xԤƽȥx(0x11)
(1)úxĴʽʾÿijɱΪ__________ԪÿijΪ__________Ԫ
(2)ߵÿy(Ԫ)x֮ĺϵʽ
(3)ߵΪwԪxΪֵʱǶԪ
ע(ÿߵijۣÿߵijɱ)
1(2012Ĵɽ)κyax2bx1(a0)ͼĶڵһޣҹ(1,0)tab1tֵı仯Χ( )
A0t1 B0t2 C1t2 D1t1 2(2012ɽ)֪κyax2bxcͼͼʾôһκybxc
a
ͷyͬһƽֱϵеͼ( )'
x
3(2012Ϻ)yxxƽ2λߵıʽ________
2
4(2012ɽׯ)κyx22x3ͼͼʾy0ʱԱxȡֵΧ______________
(4ͼ)
5(2012㶫麣)ͼκy(x2)2mͼyύڵCBǵCڸöκͼĶԳԳƵĵ㣮֪һκykxbͼöκͼϵA(1,0)B.
7 ҳ 13 ҳ
(5ͼ)
(1)κһκĽʽ
(2)ͼдkxb(x2)2mxȡֵΧ
6(2012)֪ͼya(x1)2cxύڵA(130)͵BxϷۣPڵP(1,3)
(1)ԭߵĽʽ
(2)ѧУаƱ꼶5СڽʱУPxƽ߽CD㣬ۺõͼֱCDϵIJȥƳһW͵İգ5ƴͷĸΪWWͼƴչᣬԢԶСͨ
51
ķWͼĸ(CD)ıȷdzӽƽָ(Լ0.618)
2
WͼĸıȵǶ٣(οݣ52.23662.449ɱ)
1yx6x5ĶΪ( ) A(34) B(3,4) C(34) D(3,4)
2ɶκy2(x3)21֪( ) AͼĿ
BͼĶԳΪֱx3 CСֵΪ1
Dx3ʱyx
3֪y(k3)x22x1ͼxн㣬kȡֵΧ( ) Ak4 Bk4
Ck4k3 Dk4k3
4ͼƽֱϵУͬĶԳᣬйϵȷ( )
2
8 ҳ 13 ҳ