题目内容
(1)-22+(-
)-2-
-(1-tan30°)+2sin45°
(2)解方程:x2-|x-1|-1=0.
| 1 |
| 2 |
(1-
|
(2)解方程:x2-|x-1|-1=0.
(1)-22+(-
)-2-
-(1-tan30°)+2sin45°
=-4+
-(
-1)-(1-
)+2×
,
=-4+4-
+1-1+
+
=
;
(2)x2-|x-1|-1=0.
①当x-1≥0,
∴x2-x+1-1=0.
∴x2-x=0,
解得:x=0(不合题意舍去)或x=1,
②当x-1<0,
∴x2+x-1-1=0.
∴x2+x-2=0,
解得:x=1(不合题意舍去)或x=-2,
∴x1=1,x2=-2.
| 1 |
| 2 |
(1-
|
=-4+
| 1 | ||
(-
|
| 2 |
| ||
| 3 |
| ||
| 2 |
=-4+4-
| 2 |
| ||
| 3 |
| 2 |
=
| ||
| 3 |
(2)x2-|x-1|-1=0.
①当x-1≥0,
∴x2-x+1-1=0.
∴x2-x=0,
解得:x=0(不合题意舍去)或x=1,
②当x-1<0,
∴x2+x-1-1=0.
∴x2+x-2=0,
解得:x=1(不合题意舍去)或x=-2,
∴x1=1,x2=-2.
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