Question

Find the magnitude of the vector $\overrightarrow{a}=2\hat{i}-6\hat{j}-3\hat{k}$.

Answer 1

$\overrightarrow{a}=2\hat{i}-6\hat{j}-3\hat{k}$

Magnitude of $\overrightarrow{a}=|\overrightarrow{a}|=\sqrt{(2{)}^2+(-6{)}^2+(-3{)}^2}$

$=\sqrt{4+36+9}=\sqrt{49}=7$ units