Question

The direction cosines of the vector $2\hat{i}+2\hat{j}-\hat{k}$ are ______________.

Answer 1

Direction cosines of the vector $2\hat{i}+2\hat{j}-\hat{k}$ is given by $\frac{2}{\sqrt{2^2+2^2+1^2}},\frac{2}{\sqrt{2^2+2^2+1^2}},\frac{-1}{\sqrt{2^2+2^2+1}}$
i.e $\frac{2}{3},\frac{2}{3},\frac{-1}{3}$ are the direction cosines.