Question

Determine o valor aproximado do módulo do vetor VAB, sendo A = (1, 1, 2) e B = (2, 3, -1)

Answer 1

V = A x B

V = (1, 1, 2) x (2, 3, -1)

$V=\left[\begin{array}{ccc}i&j&k\\1&1&2\\2&3&-1\end{array}\right]$

V = determinante

V = - 7i + 5j + k

V = < - 7, 5, 1 >

$|V|=\sqrt{(-7)^{2}+5^{2}+1^{2}}\\\\|V|=\sqrt{49+25+1}\\\\|V|=\sqrt{75}\\\\|V|=5\sqrt{3}$