(n＝0,1,2,…,5)组成的图形中,矩形共有   (    )

　A.25个                                                       

B.36个                           

C.100个                                                     

D.225个

A.2－sin2x                                                  

B.2＋sin2x

C.2－cos2x                                                 

D.2＋cos2x

A.(0,90°)                                                    

B.[30°,60°]

C.[60°,90°]                                          

D.[30°,90°]

n≥1时,a_n＝(    )

  A.2ⁿ                                                                                                         

B.n(n＋1)

C.2^n－1                                                                                                                       

D.2ⁿ－1

A.                        

B.                     

C.                      

D.3

A.0                          

B.32                               

C.－27                           

D.27

垂直于x轴,且∠F₁MF₂＝60°,则椭圆的离心率为 (    )

A.                                                           

B.                     

C.                                                        

D.

A.｛x|－1≤x≤1｝                                  

B.｛x|－2≤x≤2｝

C.｛x|0≤x≤2｝                                     

D.｛x|－2≤x≤0｝

A.5(1－38i)

B.5(1＋38i)                                          

C.1＋38i                                                      

D.1－38i

（ⅰ）f（－1）=f（1）=0；

（ⅱ）对任意的u，v∈［－1，1］，都有|f（u）－f（v）|≤|u－v|.

（Ⅰ）证明：对任意的x∈［－1，1］，都有x－1≤f（x）≤1－x；

（Ⅱ）判断函数g（x）=，是否满足题设条件；

（Ⅲ）在区间［－1，1］上是否存在满足题设条件的函数y=f（x），且使得对任意的u，v∈［－1，1］，都有|f（u）－f（v）|=|u－v|.

若存在，请举一例；若不存在，请说明理由.