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10. 解:(1)∵點(diǎn)在反比例函數(shù)圖象上,

,

即反比例函數(shù)關(guān)系式為;

∵點(diǎn)在反比例函數(shù)圖象上,

,

∵點(diǎn)在一次函數(shù)的圖象上,

,

解得

∴一次函數(shù)關(guān)系式為.

(2)當(dāng)時(shí),一次函數(shù)值為2,

,

.

試題詳情

9. 乙題:

解:(1)因?yàn)榉幢壤瘮?shù)的圖象經(jīng)過(guò)點(diǎn)

,················································································································ 2分

.····················································································································· 3分

所以反比例函數(shù)的解析式為,············································································· 4分

(2)當(dāng)為一、三象限角平分線與反比例函數(shù)圖像的交點(diǎn)時(shí),

線段最短.············································································································ 5分

代入,解得,即.····················· 6分

,··········································································································· 7分

,··········································································································· 8分

為反比例函數(shù)圖像上的任意兩點(diǎn),

由圖象特點(diǎn)知,線段無(wú)最大值,即.·················································· 9分

試題詳情

8.解:(1)∵反比例函數(shù)的圖像經(jīng)過(guò)點(diǎn)A(1,3),

       ∴,即m=-3.

       ∴反比例函數(shù)得表達(dá)式為.             ……3分

       ∵一次函數(shù)y=kx+b的圖像經(jīng)過(guò)A(1,-3)、C(0,-4),

       ∴  解得

       ∴一次函數(shù)的表達(dá)式為y=x-4               ……3分

(2)由消去y,得x2-4x+3=0.

   即(x-1)(x-3)=0.

   ∴x=1或x=3.

   可得y=-3或y=-1.

于是

而點(diǎn)A的坐標(biāo)是(1,-3),

∴點(diǎn)B的坐標(biāo)為(3,-1)!                    ……2分

試題詳情

7. 解:(1)設(shè)藥物燃燒階段函數(shù)解析式為,由題意得:

························································································································ 2分

此階段函數(shù)解析式為······································································· 3分

(2)設(shè)藥物燃燒結(jié)束后的函數(shù)解析式為,由題意得:

·························································································································· 5分

此階段函數(shù)解析式為······································································ 6分

(3)當(dāng)時(shí),得···················································································· 7分

························································································································· 8分

·························································································································· 9分

從消毒開(kāi)始經(jīng)過(guò)50分鐘后學(xué)生才可回教室.···························································· 10分

試題詳情

6. 解 (Ⅰ)∵點(diǎn)P(2,2)在反比例函數(shù)的圖象上,

.即. ···································································································· 2分

∴反比例函數(shù)的解析式為

∴當(dāng)時(shí),. ···························································································· 4分

(Ⅱ)∵當(dāng)時(shí),;當(dāng)時(shí),,  ····················································· 6分

又反比例函數(shù)時(shí)值隨值的增大而減小, ············································· 7分

∴當(dāng)時(shí),的取值范圍為.································································ 8分

試題詳情

5. (1)證明:分別過(guò)點(diǎn)C、D作

垂足為G、H,則

(2)①證明:連結(jié)MF,NE

設(shè)點(diǎn)M的坐標(biāo)為,點(diǎn)N的坐標(biāo)為

∵點(diǎn)M,N在反比例函數(shù)的圖象上,

,

由(1)中的結(jié)論可知:MN∥EF。

②MN∥EF。

試題詳情

4. 解:(1)由題意可知,

解,得 m=3.     ………………………………3分

A(3,4),B(6,2);

k=4×3=12.   ……………………………4分

(2)存在兩種情況,如圖: 

①當(dāng)M點(diǎn)在x軸的正半軸上,N點(diǎn)在y軸的正半軸

上時(shí),設(shè)M1點(diǎn)坐標(biāo)為(x1,0),N1點(diǎn)坐標(biāo)為(0,y1).

∵ 四邊形AN1M1B為平行四邊形,

∴ 線段N1M1可看作由線段AB向左平移3個(gè)單位,

再向下平移2個(gè)單位得到的(也可看作向下平移2個(gè)單位,再向左平移3個(gè)單位得到的).

由(1)知A點(diǎn)坐標(biāo)為(3,4),B點(diǎn)坐標(biāo)為(6,2),

N1點(diǎn)坐標(biāo)為(0,4-2),即N1(0,2);    ………………………………5分

M1點(diǎn)坐標(biāo)為(6-3,0),即M1(3,0).    ………………………………6分

設(shè)直線M1N1的函數(shù)表達(dá)式為,把x=3,y=0代入,解得

∴ 直線M1N1的函數(shù)表達(dá)式為. ……………………………………8分

②當(dāng)M點(diǎn)在x軸的負(fù)半軸上,N點(diǎn)在y軸的負(fù)半軸上時(shí),設(shè)M2點(diǎn)坐標(biāo)為(x2,0),N2點(diǎn)坐標(biāo)為(0,y2). 

ABN1M1ABM2N2,ABN1M1,ABM2N2,

N1M1M2N2,N1M1M2N2.  

∴ 線段M2N2與線段N1M1關(guān)于原點(diǎn)O成中心對(duì)稱.   

M2點(diǎn)坐標(biāo)為(-3,0),N2點(diǎn)坐標(biāo)為(0,-2).   ………………………9分

設(shè)直線M2N2的函數(shù)表達(dá)式為,把x=-3,y=0代入,解得,

∴ 直線M2N2的函數(shù)表達(dá)式為.   

所以,直線MN的函數(shù)表達(dá)式為.  ………………11分

(3)選做題:(9,2),(4,5).  ………………………………………………2分

試題詳情

3. 解:(1) ………(每個(gè)點(diǎn)坐標(biāo)寫(xiě)對(duì)各得2分)………………………4分

(2) ∵    ∴…1分

  ∴ …………………1分

      ∴ …………………2分

 (3)  ①

∴相應(yīng)B點(diǎn)的坐標(biāo)是 …………………………………………1分

∴. ………………………………………………………………1分

 ②  能  ……………………………………………………………………1分

   當(dāng)時(shí),相應(yīng),點(diǎn)的坐標(biāo)分別是,

經(jīng)經(jīng)驗(yàn):它們都在的圖象上

 …………………………………………………………………1分

試題詳情

2. 解:(1)(-4,-2);(-m,-)

(2) ①由于雙曲線是關(guān)于原點(diǎn)成中心對(duì)稱的,所以O(shè)P=OQ,OA=OB,所以四邊形APBQ一定是平行四邊形

②可能是矩形,mn=k即可

不可能是正方形,因?yàn)镺p不能與OA垂直。

解:(1)作BE⊥OA,

∴ΔAOB是等邊三角形

∴BE=OB·sin60o=,

∴B(,2)

∵A(0,4),設(shè)AB的解析式為,所以,解得,的以直線AB的解析式為

(2)由旋轉(zhuǎn)知,AP=AD, ∠PAD=60o,

∴ΔAPD是等邊三角形,PD=PA=

試題詳情

1. 證明:(1)分別過(guò)點(diǎn)C,D,作CGAB,DHAB,

垂足為G,H,則∠CGA=∠DHB=90°.……1分

CGDH.  

∵ △ABC與△ABD的面積相等, 

CGDH.   …………………………2分

∴ 四邊形CGHD為平行四邊形. 

ABCD.  ……………………………3分

(2)①證明:連結(jié)MF,NE.  …………………4分

設(shè)點(diǎn)M的坐標(biāo)為(x1,y1),點(diǎn)N的坐標(biāo)為(x2y2).

∵ 點(diǎn)M,N在反比例函數(shù)(k>0)的圖象上,

,. 

MEy軸,NFx軸, 

OEy1,OFx2

SEFM,   ………………5分

SEFN.   ………………6分

SEFM SEFN       ……

由(1)中的結(jié)論可知:MNEF.  ………8分

MNEF.      …………………10分

(若學(xué)生使用其他方法,只要解法正確,皆給分.

試題詳情


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