Question

Given vector a = 2i + 2j + k and c = pi + qj , find value p and q for which c is a unit vector perpendicular to a

Answer 1

do you know how to take the dot product of two vectors?

Answer 2

Yup, but I need another equation

Answer 3

c = pi + qj

Answer 4

Does magnitude of c equal to one ?

Answer 5

it should

Answer 6

p^2 + q^2 = 1 ---> (c is unit vector)
2p+2q=0 => p=-q (as 'a' dot product 'c' = 0)