问题
填空题
已知|
|
答案
∵|
|=2,|a
|=5,b
•a
=-3b
|
-a
|2b
=
2+a
2-2b
•a b
=4+25-2×(-3)
=35
∴|
-a
|=b 35
故答案为:35
已知|
|
∵|
|=2,|a
|=5,b
•a
=-3b
|
-a
|2b
=
2+a
2-2b
•a b
=4+25-2×(-3)
=35
∴|
-a
|=b 35
故答案为:35