问题
解答题
(1)-22+(-
(2)解方程:x2-|x-1|-1=0. |
答案
(1)-22+(-
)-2-1 2
-(1-tan30°)+2sin45°(1-
)22
=-4+
-(1 (-
) 21 2
-1)-(1-2
)+2×3 3
,2 2
=-4+4-
+1-1+2
+3 3 2
=
;3 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.