问题 填空题
△ABC中,∠C=90°,且CA=CB=3,点M满足
BM
=2
AM
,则
CM
CA
=______.
答案

由题意,

CM
CA
=(
CB
+
BM
)•
CA
=
CB
CA
+
BM
CA

∵∠C=90°,且CA=CB=3,点M满足

BM
=2
AM

CB
CA
+
BM
CA
=
2
3
BA
CA
=
2
3
×3
2
×3×cos45°
=6

CM
CA
=6

故答案为:6

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