Question

find the cross product between a(7,-1,5) and b(9,3,2)​

Answer 1

Explanation:

formula : if a(a1, a2 ,a3) b(b1, b2, b3)

a×b = (a2b3 - a3b2 ,a3b1 - a1b3, a1b2 - a2b1 )

= ( a2b3 - a3b2)i + ( a3b1 - a1b3 ) j + ( a1b2 - a2b1 )k

so , a1 = 7 a2 = -1 a =5

b1 = 9 b2 = 3 b3 = 2

= [( -1×2) -(5×3)] I + [(5×9) - (7×2)] j + [(7×3) - (+1×9)]k

=(-2-15)i + (45-14)j + (21 +9)k

= -17i +31 j +30 k

hope this would help u ...

thank u...