Question:
Let $\overrightarrow{\mathrm{A}}=(\hat{\mathrm{i}}+\hat{\mathrm{j}})$ and $\overrightarrow{\mathrm{B}}=(\hat{\mathrm{i}}-\hat{\mathrm{j}})$. The magnitude of a coplanar vector $\overrightarrow{\mathrm{C}}$ such that $\overrightarrow{\mathrm{A}} \cdot \overrightarrow{\mathrm{C}}=\overrightarrow{\mathrm{B}} \cdot \overrightarrow{\mathrm{C}}=\overrightarrow{\mathrm{A}} \cdot \overrightarrow{\mathrm{B}}$ is given by
$\sqrt{\frac{5}{9}}$
$\sqrt{\frac{10}{9}}$
$\sqrt{\frac{20}{9}}$
$\sqrt{\frac{9}{12}}$
Question of from chapter.
JEE Main Previous Year April 16, 2018
Correct Option: 1
Solution: