第四章指数函数与对数函数4.1指数 4.1.2无理数指数幂及其
运算性质
学校:___________姓名:___________班级:___________考号:___________
一、单选题
1.化简:(??4)2???( ) A.4
B.2??4
C.2??4或4
2.已知xy?0且4x2y2??2xy,则有( ) A.xy?0
B.xy?0
C.x?0,y?0
3.设2?a?3,则(2?a)2?4(3?a)4化简的结果为( )A.1
B.-1
C.2a?5 4.化简3[3(?5)2]4的结果为( )
A.5
B.5 C.?5 5.已知a?0,将
a2a?3a2表示成分数指数幂,其结果是( )
A.
1B.
37a2 a4 C.
a6 6.下列运算正确的是( )
71A.??m??n???m7?n7(m?0,n?0) B.12(?3)4?3?3C.34x3?y3?(x?y)4(x?0,y?0)
D.39?33 7.下列运算中,正确的是( ) A.x3x2x5 B.x?x2?x3
C.2x3?x2?x
028.?3??11?2????1?0.5?2????27?的值为( ?8? )
?A.?13
B.
13 C.
43 9.化简25(2a?3b?3)?(?3a?1b)?(4a?4b?3)(a,b?0)得( )
D.4?2?
D.x?0,y?0
D.5?2a
D.?5
D.
3a2
3D.??x?x3?2???2
D.
73 32
A.?b
232B.b
237C.?b3
237D.b3
210.若102x?25,则10?x等于( ) A.
1 5B.
2 5C.
4 5D.
4 2511.若x?x?1?3,那么x2?x?2的值为( ) A.?35 12. 若a2xA.22?1 C.22?1
13.若3a?5,3??6,则
B.?5 C.35
D.13 a3x?a?3x 等于 ?2?1,则x?xa?aB.2?22 D.2?1
125?( ) 36C.3a3?3?A.???2?????1
4B.33??2?
?3??3
D.325??6?
14.化简3??A.
?8a?(其中a?0,b?0)的结果是( ) 3??27b?B.?2a 3b2a 3b2C.
16
81b4a4D.?1
81b4a415.已知二次函数f(x)?ax?bx?0.1?a?0?的图象如图所示,则4(a?b)4的值为( )
A.a?b
B.?(a?b)
C.a?b D.b?a
11111???????????????16.化简?1?232??1?216??1?28??1?24??1?22?,结果是( )
??????????1??1?A.?1?232?
2???11???32B.?1?2? ???1C.
1?21?32
1??1?D.?1?232?
2??
二、填空题
x217.若x?0,则|x|?x??__________.
|x|218.使等式(x?5)x2?25?(5?x)x?5成立的x的取值范围是__________.
1121??51?1?319.化简:a2b3?(?3a6b)?(4a3b)2?_________.
6??20.a3b23ab2(ab)ab14124?1313?________(a?0,b?0).
21.若x2?2x?1?121?2y2?6y?9?0,则?x2017?y?__________.
2a?1__________.
22.设,则?a?a?ma23.若代数式2x?1?2?x有意义,则4x2?4x?1?24(x?2)4?_________. 24.已知a?ax2?x2??5(a?0,x?R),则a2?a2?____________
3x3x325.已知m=2,n=3,则[m2n?3n?3m?2÷mn?4nm?2]3的值是______.
243a3a2?_________. ?b?,则a26.已知
b233?27
三、解答题
27.已知a?b?0,n?1,n?N?,化简n?a?b??n?a?b?. 28.化简: (1)nna355b2?3b3a34(a?0,b?0);
a?1?b?1(2)?1?1.
a?b29.(1)化简:3xy2?xy?1?xy?(xy)?1(xy?0); (2)计算:2?122(?4)010???(1?5)?83.
22?1