问题
解答题
(1)计算:
(2)|-
|
答案
(1)原式=
-22(
+1)2 2-1
-1,2
=2
+2-22
-1,2
=1;
(2)原式=
+1 2
+2×(1 2
)2-2 2
×(1 3
)2,3
=
+1 2
+1-1,1 2
=1.
(1)计算:
(2)|-
|
(1)原式=
-22(
+1)2 2-1
-1,2
=2
+2-22
-1,2
=1;
(2)原式=
+1 2
+2×(1 2
)2-2 2
×(1 3
)2,3
=
+1 2
+1-1,1 2
=1.
A.方向向上,2 ×106 N
B.方向向下,2 ×106 N
C.方向向上,1.8 ×107 N
D.方向向下,1.8 ×107 N