Two non-zero vectors and make an angle of with each other

MATHEMATICS · Single correct · CBSE · Mathematics · Vector Algebra · Vector Algebra

Problem

Two non-zero vectors

\vec P

and

\vec Q

make an angle of

120^{\circ}

with each other. The scalar projection of

\vec P

\vec Q

is (a)

+\;P\cos60^{\circ}

(b)

+\;P\cos120^{\circ}

(c)

-\;P\cos120^{\circ}

(d)

0