What is the cross product of #<5 , 5 ,-7 ># and #<5 ,6 ,-3 >#?

1 Answer
Oct 29, 2016

Answer:

#<27, -20, 5>#

Explanation:

Convert to #hati, hatj, hatk# notation

#barA = 5hati + 5hatj - 7hatk#
#barB = 5hati + 6hatj - 3hatk#

The cross product can be computed using a determinant:

#barA xx barB = | (hati, hatj, hatk, hati, hatj), (5, 5, - 7,5, 5), (5, 6, -3, 5, 6) | = #

#{(5)(-3)-(-7)(6)}hati + {(-7)(5) - (5)(-3)}hatj + {(5)(6) - (5)(5)}hatk = #

#27hati - 20hatj + 5hatk#