△ABC中,∠BAC=60°,AB=1,AC=3,D在AC上,且AD =2 DC ,则 BA • AD = BA -1 EA -1 .
△ABC中,∠BAC=60°,AB=1,AC=3,D在AC上,且AD =2 DC ,则 BA • AD = BA -1 EA -1 .
发布时间:2025-06-24 11:19:12
△ABC中,∠BAC=60°,AB=1,AC=3,D在AC上,且AD =2 DC ,则 BA • AD = BA -1 EA -1 .