On the problem of vector cross product Vector Ba = 1 / 2 (2 vector a + vector b-vector C) vector BC = 1 / 2 (vector a + vector C) ask vector Ba cross product vector BC =?

On the problem of vector cross product Vector Ba = 1 / 2 (2 vector a + vector b-vector C) vector BC = 1 / 2 (vector a + vector C) ask vector Ba cross product vector BC =?

The formula is a × a = 0, a × B = - B × a
BA×BC=1/2(2a+b-c)×1/2(a+c)
=1/4(2a×c+b×a+b×c-c×a)
=1/4(3a×c+b×a+b×c)