问题
填空题
△ABC中,∠C=90°,且CA=CB=3,点M满足
|
答案
由题意,
•CM
=(CA
+CB
)•BM
=CA
•CB
+CA
•BM CA
∵∠C=90°,且CA=CB=3,点M满足
=2BM
,AM
∴
•CB
+CA
•BM
=CA 2 3
•BA
=CA
×32 3
×3×cos45°=62
∴
•CM
=6CA
故答案为:6
△ABC中,∠C=90°,且CA=CB=3,点M满足
|
由题意,
•CM
=(CA
+CB
)•BM
=CA
•CB
+CA
•BM CA
∵∠C=90°,且CA=CB=3,点M满足
=2BM
,AM
∴
•CB
+CA
•BM
=CA 2 3
•BA
=CA
×32 3
×3×cos45°=62
∴
•CM
=6CA
故答案为:6