Mathematics for IGCSE & O level - Vectors (Section 1 - No. 2)
In a triangle ABC, where D is the midpoint of BC, which of the following is/are true?
\(\vec{BD} = \vec{DC}\)
\(\vec{AD} = \frac{1}{2}(\vec{AB} + \vec{AC})\)
\(\vec{AB} + \vec{BC} + \vec{CA} = \vec{0}\)
D lies on AB
Giải thích
BD and DC are equal because D is the midpoint, AD = 1/2(AB + AC), and AB + BC + CA = 0. D is on BC not AB.