Mathematics - Vector Question with Solution | TestHub

Two points, P and Q, are given in the rectangular Cartesian coordinate system on the curve $y=2^{x+2}$, such that $\overrightarrow{OP}\cdot \hat{i}=-1$ and $\overrightarrow{OQ}\cdot \hat{i}=2$. The magnitude of the vector $\overrightarrow{OQ}-4\overrightarrow{OP}$ is $10l$, where $l=\_$. (Here, O is the origin.)