问题:
已知
a
=(cosα,sinα),
b
=(cosβ,sinβ),0<β<α<π.
(1)若|
a
-
b
|=
2
,求证:
a
⊥
b
;
(2)设
c
=(0,1),若
a
+
b
=
c
,求α,β的值.
已知
=(cosα,sinα),
=(cosβ,sinβ),0<β<α<π.
(1)若|
-
|=
,求证:
⊥
;
(2)设
=(0,1),若
+
=
,求α,β的值.
a |
b |
(1)若|
a |
b |
2 |
a |
b |
(2)设
c |
a |
b |
c |
参考答案: