问题
解答题
(1)解不等式2x2+2x-4≤
(2)计算log2
|
答案
(1)不等式2x2+2x-4≤
可化为2x2+2x-4≤2-1,1 2
∴x2+2x-4≤-1,即x2+2x-3≤0.
解得-3≤x≤1.
(2)原式=lo
-1g (
×48 7
×1 12
)242
=lo
-1g
22
=
-1=-1 2
.1 2
(1)解不等式2x2+2x-4≤
(2)计算log2
|
(1)不等式2x2+2x-4≤
可化为2x2+2x-4≤2-1,1 2
∴x2+2x-4≤-1,即x2+2x-3≤0.
解得-3≤x≤1.
(2)原式=lo
-1g (
×48 7
×1 12
)242
=lo
-1g
22
=
-1=-1 2
.1 2