# Mark against the correct answer in each of the following:

Question:

Mark $(\sqrt{)}$ against the correct answer in each of the following:

The direction cosines of the vector $\overrightarrow{\mathrm{a}}=(-2 \hat{\mathrm{i}}+\hat{\mathrm{j}}-5 \hat{\mathrm{k}})$ are

A. $-2,1,-5$

B. $\frac{1}{3}, \frac{-1}{6}, \frac{-5}{6}$

C. $\frac{2}{\sqrt{30}}, \frac{1}{\sqrt{30}}, \frac{5}{\sqrt{30}}$

D. $\frac{-2}{\sqrt{30}}, \frac{1}{\sqrt{30}}, \frac{-5}{\sqrt{30}}$

Solution: