Question

What is the condition for web two vectors to be parallel or perpendicular to each other?

Answer 1

1.Vectors A and B are perpendicular if and only if A·B = 0

2.Unit vector along direction of vector A is n=A/|A|.

In our problem A=3i+7j+4k and |A|=sqrt [9+49+16]=sqrt(74).

Therefore, unit vector asked for =(3/74)i +(7/74)j+(4/74)k.