题目内容
观察下列二次根式的化简,
=
-1,
= ,找出规律,并计算(
+
+
+…+
)(
+1)= .
| 1 | ||
|
| 2 |
| 1 | ||||
|
| 1 | ||
|
| 1 | ||||
|
| 1 | ||||
|
| 1 | ||||
|
| 2014 |
考点:分母有理化
专题:
分析:分子分母都乘以
-
,即可求出答案;根据规律得出原式=(
-1+
-
+
-
+…+
-
)(
+1),推出(
-1)(
+1),求出即可.
| 3 |
| 2 |
| 2 |
| 3 |
| 2 |
| 4 |
| 3 |
| 2014 |
| 2013 |
| 2014 |
| 2014 |
| 2014 |
解答:解:
=
=
-
,
(
+
+
+…+
)(
+1)=
=(
-1+
-
+
-
+…+
-
)(
+1)
=(
-1)(
+1)
=2014-1
=2013,
故答案为:
-
,2013.
| 1 | ||||
|
=
1×(
| ||||||||
(
|
=
| 3 |
| 2 |
(
| 1 | ||
|
| 1 | ||||
|
| 1 | ||||
|
| 1 | ||||
|
| 2014 |
=(
| 2 |
| 3 |
| 2 |
| 4 |
| 3 |
| 2014 |
| 2013 |
| 2014 |
=(
| 2014 |
| 2014 |
=2014-1
=2013,
故答案为:
| 3 |
| 2 |
点评:本题考查了分母有理化和平方差公式的应用,解此题的关键是能根据求出的结果得出规律.
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