参考答案
一、单选题
1 2 3 4 5 6 7 8 9 10
C B C A D B A C A B
二、填空题
11、 5
x≥
3
12、 <
13、 3
14、 直角
15、 -1
16、 2
17、 (数据不全)
18、 ②③
三、解答题
19、 √8 + (π 3.14)0 |1 √2|
= 2√2 + 1 √2 +1
= √2+2
20、 2
(3 + √5)(3 √5) + (√2 √3)
= 32 5 + 2 + 3 2√6
= 9 2√6
21、 2 1
x2 1 x 1
2 (x + 1)
=
x2 1
1 x
=
x2 1
1
=
x + 1
22、 1 4x 2
+ =
x + 2 x2 4 x 2
x 2 + 4x 2x + 4
=
x2 4 x2 4
5x 2 = 2x + 4
3x = 6
x = 2
与方程定义 x≠±2矛盾
所以方程无解
23、 1 3 x 1
( ) +
x 2 x2 4 x + 2
x + 2 3 + (x 1)(x 2)
=
x2 4
(x 1)2
=
x2 4
其中x = 2 + √2
(x 1)2
x2 4
(x 1)2
=
(x + 2)(x 2)
2
(2 + √2 1)
=
(2 + √2 + 2)(2 + √2 2)
2
(1 + √2)
=
√2(4 + √2)
3 + 2√2
=
√2(4 + √2)
4√2 + 5
=
14
24、 2x + m
= 1
x + 1
2x + m = x + 1
x = 1 m
∵x 为负数
1 m < 0,1 m ≠ 1
∴m > 1,m ≠ 2
25、 x2 3xy + y2
= (x y)2 xy
2
= (√3 + √2 √3 + √2) (√3 + √2)(√3 √2)
= 8 1
= 7
26、 设甲种排球单价为 x 元
1950 2250
=
x x + 10
1950(x + 10) = 2250x
300x = 19500
x = 65
甲种排球单价为 65 元,乙种排球单价为 75 元
27、 (1)2,π-3
(2)x≤2
(3)a<0,c-a>0,c+b>0
√a2 |c a| + √(c + b)2
= a c + a + c + b
= b
28、 (1)
(2)60°,75°
29、 (1)≥
(2)>
1
(3)√7 √6 =
√7+√6
1
√6 √5 =
√6+√5
√7 √6 (√6 √5)
1 1
=
√7 + √6 √6 + √5
√6 + √5 √7 √6
=
(√7 + √6)(√6 + √5)
√5 √7
= < 0
(√7 + √6)(√6 + √5)
∴√7 √6 < √6 √5
30、 1
(1)( , √3)
3
(2)3
1
(3) = √3
√a
1
a =
3
√b = 3√2
b = 18
ab = 6
1
(4)m = ,n = √b
√a
1
a>1 时,m = < 1
√a
1
m + n = + √b > √b
√a
√b
mn = < √b
√a
∴m+n>mn