Question

What is the cross product of `<7 ,4 ,1 >` and `<-5 ,2 ,8 >`?

Answer 1

Cross product is `< 30, -61, 34 >`

Explanation:

Cross product of `< a_1, a_2, a_3 >` and `< b_1, b_2, b_3 >` is

`< (a_2*b_3-a_3*b_2),(a_3*b_1-a_1*b_3),(a_1*b_2-a_2*b_1) >`

Hence cross product of `< 7, 4, 1 >` and `< -5, 2, 8 >`

is `< (4*8-1*2), (1*(-5)-7*8), (7*2-4*(-5)) >`

i.e. `< (32-2),(-5-56),(14+20) >`

or `< 30, -61, 34 >`