问题
解答题
解方程:2x2-4x-1=0(用配方法)
答案
2x2-4x-1=0
x2-2x-
=01 2
x2-2x+1=
+11 2
(x-1)2=3 2
∴x1=1+
,x2=1-6 2
.6 2
解方程:2x2-4x-1=0(用配方法)
2x2-4x-1=0
x2-2x-
=01 2
x2-2x+1=
+11 2
(x-1)2=3 2
∴x1=1+
,x2=1-6 2
.6 2