The vector cos α cos β i + cos α sin β j + sin α k is a A. null vector B. unit vector C. constant vector D. none of these

Question

The vector cos α cos β \(\hat i\) + cos α sin β \(\hat j\) + sin α \(\hat k\) is a

A. null vector

B. unit vector

C. constant vector

D. none of these

Answer 1

Correct option is B. unit vector

\(=\sqrt{cos^2\alpha+sin^2\alpha}\)

= \(\sqrt 1\)

= 1

Hence, the given vector is a unit vector.