Which one of the following correctly expresses the scalar (dot) product of two…

MATHEMATICS · Single correct · A Level · Mathematics · Vectors · Vectors

Problem

Which one of the following correctly expresses the scalar (dot) product of two vectors

\vec{a}

and

\vec{b}

in terms of the angle

\theta

between them? (a)

|\vec a|\,|\vec b|\sin\theta

(b)

|\vec a|\,|\vec b|\cos\theta

(c)

\dfrac{|\vec a|}{|\vec b|}\cos\theta

(d)

|\vec a|\,|\vec b|\cos^{2}\theta