2.如果.則 查看更多

 

題目列表(包括答案和解析)

如果,則下面結(jié)論中正確的個(gè)數(shù)是

xy  ②xy  ③xy的大小關(guān)系不確定  ④x2005y2005

A.1                                     B.2                                     C.3                                     D.4

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如果=+,則n的值為(    )

A.8                      B.7                     C.6                D.不存在

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如果,則使的取值范圍為( 。

    A.   B.      C.    D.

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如果,則把變量________的值增加1會(huì)使的值增加最大(填入中的某個(gè)字母).

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如果,則當(dāng)時(shí),(     )

A.        B.      C.         D.

 

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一.選擇題

1―5  CBABA   6―10  CADDA

二.填空題

11.       12.()       13.2          14.         15.

16.(1,4)

三.解答題

數(shù)學(xué)理數(shù)學(xué)理17,解:①         =2(1,0)                      (2分)             

        ?,                                        (4分)

?

        cos              =

 

        由,  ,    即B=              (6分)

                                               (7分)

                                                        (9分)

,                                                         (11分)

的取值范圍是(,1                                                      (13分)

18.解:①設(shè)雙曲線方程為:  ()                                 (1分)

由橢圓,求得兩焦點(diǎn),                                           (3分)

,又為一條漸近線

, 解得:                                                     (5分)

                                                    (6分)

②設(shè),則                                                      (7分)

      

?                             (9分)

,  ?              (10分)

                                                (11分)

  ?

?                                        (13分)

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  單減區(qū)間為[]        (6分)

 

②(i)當(dāng)                                                      (8分)

(ii)當(dāng),

,  (),,

則有                                                                     (10分)

                                               (11分)

  在(0,1]上單調(diào)遞減                     (12分)

                                                 (13分)

20.解:①       

                                                        (2分)

從而數(shù)列{}是首項(xiàng)為1,公差為C的等差數(shù)列

  即                                (4分)

 

   即………………※              (6分)

當(dāng)n=1時(shí),由※得:c<0                                                    (7分)

當(dāng)n=2時(shí),由※得:                                                 (8分)

當(dāng)n=3時(shí),由※得:                                                 (9分)

當(dāng)

    (

                                          (11分)

                         (12分)

綜上分析可知,滿足條件的實(shí)數(shù)c不存在.                                    (13分)

21.解:①設(shè)過A作拋物線的切線斜率為K,則切線方程:

                                                                (2分)

    即

                                                                                                   (3分)

②設(shè)   又

     

                                                         (4分)

同理可得 

                                                (5分)

又兩切點(diǎn)交于  ,

                               (6分)

③由  可得:

 

                                                (8分)

                  (9分)

 

當(dāng) 

當(dāng) 

                                                     (11分)

當(dāng)且僅當(dāng),取 “=”,此時(shí)

                                       (12分)

22.①證明:由   

  即證

  ()                                    (1分)

當(dāng)  

      即:                          (3分)

  ()    

當(dāng)   

   

                                                         (6分)

②由      

數(shù)列

                                              (8分)

由①可知, 

                    (10分)

由錯(cuò)位相減法得:                                       (11分)

                                    (12分)

 

 


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