Question

dados os pontos A(2,-1,2),B(1,2,-1) e C(3,2,1). Determine o vetor CB×(BC-2CA)

Answer 1

CB=B-C OU SEJA(1-3,2-2,-1-1)=(-2,0,-2)
2CA=2(A-C)=(-1,-3,1) =(-2,-6,2)
BC=C-B=(2,0,2)
LOGO CB*(BC-2AC)=(-2,0,-2)*(4,6,0)=(-8,0,0)