Question

Guys Please answer this
I am very confused​

Answer 1

Since these two vectors are perpendicular so

(2i+3j+8k).(4i-4j+ak) = 0. ( a = alpha)

Now,

2.4-3.4+8a = 0

8-12+8a = 0

8a = 4

a = 1/2

Remember that (i.i) = 1 = j. j= k. k but i. j = 0 and so on