Даны векторы; a = {2;— 3; 1}, b = {— 3;1;2} и c = {1;2;3}. Вычислить [[ab] с] и [a [bc]}.

Question

Даны векторы; a = {2;— 3; 1}, b = {— 3;1;2} и c = {1;2;3}. Вычислить [[ab] с] и [a [bc]}.

Answer 1

[ab] = i*(-3*2-1*1) +j*(1*(-3)-2*2) +k*(2*1-(-3)*(-3)) = -7i -7j -7k
[[ab] с] = i*(-7*3+7*2) +j*(-7*1+7*3) + k*(-7*2+7*1) = -7i +14j -7k
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[bc] = i*(1*3-2*2) +j*(2*1+3*3) +k*(-3*2-1*1) = -1i +11j -7k
[a [bc]]  = i*(-3*(-7)-1*(-11)) +j*(1*(-1)-2*(-7)) +k*(2*11+3*(-1)) = -10i +13j +19k