Determine all real values of for which the angle between the vectors and is .

MATHEMATICS · Subjective · CBSE · Mathematics · Vector Algebra · Vector Algebra

Problem

Determine all real values of

k

for which the angle between the vectors

\vec a=\mathbf{i}+2\mathbf{j}+k\mathbf{k}

and

\vec b=2\mathbf{i}-\mathbf{j}+2\mathbf{k}

60^{\circ}