# What is the cross product of [-1, -1, 2] and [1, -4, 0] ?

Mar 7, 2016

#### Answer:

$\vec{a} x \vec{b} = 8 i + 2 j + 5 k$

#### Explanation:

$\vec{a} = \left[- 1 , - 1 , 2\right] \text{ } \vec{b} = \left[1 , - 4 , 0\right]$
$\vec{a} x \vec{b} = i \left(- 1 \cdot 0 + 4 \cdot 2\right) - j \left(- 1 \cdot 0 - 2 \cdot 1\right) + k \left(1 \cdot 4 + 1 \cdot 1\right)$
$\vec{a} x \vec{b} = 8 i + 2 j + 5 k$