jika titik koordinat titik A(4,-2)B(1,3)dan C (-3,2)hasil dari AB.BC

[tex]AB = B - A \\ AB = (1,3) - (4,-2) \\ AB = (-3,5) \\ \\ BC = C-B \\ BC=(-3,2)-(1,3) \\ BC=(-4,-1) \\ \\ AB.BC=(-3,5).(-4,-1) \\ AB.BC=12 - 5 \\ AB.BC=7[/tex]

Matematika X SMA
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Pembahasan :
AB = b - a
AB = [1 3] - [4 -2]
AB = [(1 - 4) (3 + 2)]
AB = [-3 5]

BC = c - b
BC = [-3 2] - [1 3]
BC = [(-3 - 1) (2 - 3]
BC = [-4 -1]

Maka...
AB . BC
= [-3 5] . [-4 -1]
= (-3).(-4) + (5)(-1)
= 12 - 5
= 7