问题
解答题
(1)当t=
(2)计算
|
答案
(1)∵t=
,1 8
∴
+t+1
+13 t
-t-1
+3 t2
+13 t t- 3 t
-13 t
=
-3 t2
+1+3 t
-1-3 t t- 3 t
-13 t
=
-3 t2 t- 3 t
-13 t
=
-3 1 64
-1 8 3 1 8
-13 1 8
=
-1 4
=-3 4
.1 2
(2)2lg2+lg3 1+
lg0.36+1 2
lg81 3
=lg(4×3) lg(10×0.6×2)
=
=1.lg12 lg12