Question

Find a vector B linearly dependent on the vector A = 2i + j - k , such that A. B = 3.

Answer 1

A = 2 i + 1 j - 1 k
B = 2c i + c j - c k
A dot B = 4 c + c + c = 6 c = 3
c = 1/2
B = i + (1/2) j - (1/2) k