题目内容
观察下列各式的化简过程①
1 | ||
1+
|
2 |
1 | ||||
|
3 |
2 |
1 | ||||
|
4 |
3 |
1 | ||||
|
2007 |
2006 |
(1)写出①式具体的化简过程.
(2)利用你所观察到的规律,试计算(
1 | ||
1+
|
1 | ||||
|
1 | ||||
|
1 | ||||
|
2011 |
分析:(1)根据分数的基本性质,分子和分母都乘以(1-
),化简即可;
(2)根据(1)的结论代入后合并得出(
-1)(
+1),再根据平方差公式进行计算即可.
2 |
(2)根据(1)的结论代入后合并得出(
2011 |
2011 |
解答:解:(1)
=
=
=
=
-1.
(2)(
+
+
+…+
)×(1+
)
=(
-1+
-
+
-
+…+
-
+
-
)×(1+
)
=(
-1)×(1+
)
=2010.
1 | ||
1+
|
1×(1-
| ||||
(1+
|
=
1-
| ||
12-(
|
=
1-
| ||
1-2 |
2 |
(2)(
1 | ||
1+
|
1 | ||||
|
1 | ||||
|
1 | ||||
|
2011 |
=(
2 |
3 |
2 |
4 |
3 |
2010 |
2009 |
2011 |
2010 |
2011 |
=(
2011 |
2011 |
|
=2010.
点评:本题考查对二次根式的加减,分母有理化的理解,关键是能通过计算得出规律.
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目