# What is the cross product of [4,-3,1] and [1,-1,3] ?

$a x b = - 8 i - 11 j - k$
$a x b = i \left(- 9 + 1\right) - j \left(12 - 1\right) + k \left(- 4 + 3\right)$
$a x b = - 8 i - 11 j - k$