§ 4. Координати та вектори в просторі » 18.30
Дано паралелепіпед ABCDA1B1C1D1. Виразіть вектор (AA_1 ) ⃗ через вектори (B_1 A) ⃗, (B_1 C) ⃗ і (B_1 D) ⃗. (AA_1 ) ⃗ = (BB_1 ) ⃗ (DA) ⃗ = (B_1 A) ⃗ – (B_1 D) ⃗ (DA) ⃗ = (CB) ⃗ (B_1 C) ⃗ + (CB) ⃗ = (B_1 B) ⃗ = –(BB_1 ) ⃗ (AA_1 ) ⃗ = (BB_1 ) ⃗ = –(B_1 C) ⃗ – (CB) ⃗ = –(B_1 C) ⃗ – (DA) ⃗ = –(B_1 C) ⃗ – (B_1 A) ⃗ + (B_1 D) ⃗ = (B_1 C) ⃗ – (B_1 A) ⃗.