What is the cross product of $[9, 4, - 1]$ $[9,4,-1]$ and $[2, 1, - 4]$ $[2, 1, -4]$ ?

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Answer 1 · 2015-12-21T21:32:22

$(- 15, 34, 1)$ $(-15,34,1)$

The cross product of two 3-dimesnional vectors in $RR^3$ may be given as a matrix determinant

$(9,4,-1)xx(2,1,-4)=|(hati,hatj,hatk),(9,4,-1),(2,1,-4)|$

$hati(-16+1)-hatj(-36+2)+hatk(9-8)$

$=-15hati+34hatj+hatk$

$=(-15,34,1)$

What is the cross product of [9,4,-1][9,4,−1][9,4,-1] and [2, 1, -4] [2,1,−4][2, 1, -4] ?