What is the cross product of #<3,-6,4># and #<-1,-1,2>#?

1 Answer
Jul 13, 2017

# <3,-6,4> xx <-1,-1,2> = <-8,-10,-9> #

Explanation:

We can use the notation:

# \ \ \ \ \ ( (3),(-6),(4) ) xx ( (-1),(-1),(2) ) = | (ul(hat(i)),ul(hat(j)),ul(hat(k))), (3,-6,4),(-1,-1,2) |#

# " " = | (-6,4),(-1,2) | ul(hat(i)) - | (3,4),(-1,2) | ul(hat(j)) +| (3,-6),(-1,-1) | ul(hat(k)) #

# " " = (-12-(-4)) ul(hat(i)) - (6-(-4)) ul(hat(j)) +(-3-6) ul(hat(k)) #

# " " = -8 ul(hat(i)) - 10 ul(hat(j)) - 9 ul(hat(k)) #
# " " = ( (-8),(-10),(-9) ) #