What is the cross product of #<-2, 5 ,-2 ># and #<7 , -9 ,2 >#?

Question

1236 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-01-29T11:10:12

The answer is #=<-8,-10,-17>#

The cross product of 2 vectors #veca# and #vecb# is given by the determinant

#|((hati ,hatj,hatk ), (-2,5,-2),(7,-9,2))|#

#=hati*|((5,-2),(-9,2))|-hatj*|((-2,-2),(7,2))|+hatk*|((-2,5),(7,-9))|#

#=hati(-8)-hatj(10)+hatk(-17)#

#=<-8,-10,-17>#

Verification by doing the dot products

#<-8,-10,-17>.<-2,5,-2>=16-50+34=0#

#<-8,-10,-17>.<7,-9,2>=-56+90-34=0#