What is the cross product of <-3, -1, 8 > and <2,-4, -9 >?

1 Answer
Aug 17, 2016

((41),(-11),(14))

Explanation:

Let

vec(u) = -3vec(i) - vec(j) + 8vec(k)

vec(v) = 2vec(i) - 4vec(j) - 9vec(k)

vec(u) xx vec(v) = [(vec(i),vec(j),vec(k)),(-3,-1,8),(2,-4,-9)]

= vec(i)[(-1,8),(-4,-9)] - vec(j)[(-3,8),(2,-9)] + vec(k)[(-3,-1),(2,-4)]

=vec(i)(9+32) - vec(j)(27-16) + vec(k)(12+2)

therefore vec(u)xxvec(v) = 41vec(i) - 11vec(j) + 14vec(k)