∵AD⊥AB
∴向量AC·向量AD=0
cos=cos∠ADB=|向量AD|/|向量BD|
∴向量AC·向量AD
=(向量AB+向量BC)·向量AD
=向量AB·向量AD+向量BC·向量AD
=向量BC·向量AD
=(√3)向量BD·向量AD
=(√3)|向量BD|×|向量AD|×cos
=(√3)|向量BD|×|向量AD|×(|向量AD|/|向量BD|)
=(√3)|向量AD|^2
=(√3)×1^2
=√3
∵AD⊥AB
∴向量AC·向量AD=0
cos=cos∠ADB=|向量AD|/|向量BD|
∴向量AC·向量AD
=(向量AB+向量BC)·向量AD
=向量AB·向量AD+向量BC·向量AD
=向量BC·向量AD
=(√3)向量BD·向量AD
=(√3)|向量BD|×|向量AD|×cos
=(√3)|向量BD|×|向量AD|×(|向量AD|/|向量BD|)
=(√3)|向量AD|^2
=(√3)×1^2
=√3