Let A =( i + j ) and, B =(2 i - j ). The magnitude of a coplanar vector C such that A · C = B · C = A · B, is given by:

Let $\displaystyle \overrightarrow{\mathrm{A}}=(\hat{i}+\hat{j})$ and, $\displaystyle \overrightarrow{\mathrm{B}}=(2 \hat{i}-\hat{j})$. The magnitude of a coplanar vector $\displaystyle \vec{C}$ such that $\displaystyle \vec{A} \cdot \vec{C}=\vec{B} \cdot \vec{C}=\vec{A} \cdot \vec{B}$, is given by :