If $\overrightarrow A = 4\hat i - 3\hat j$ and $\overrightarrow B = 6\hat i + 8\hat j$ then magnitude and direction of $\overrightarrow A \, + \overrightarrow B $ will be
$5,\,{\tan ^{ - 1}}(3/4)$
$5\sqrt 5 ,{\tan ^{ - 1}}(1/2)$
$10,\,{\tan ^{ - 1}}(5)$
$25,\,{\tan ^{ - 1}}(3/4)$
Statement $I :$Two forces $(\overrightarrow{{P}}+\overrightarrow{{Q}})$ and $(\overrightarrow{{P}}-\overrightarrow{{Q}})$ where $\overrightarrow{{P}} \perp \overrightarrow{{Q}}$, when act at an angle $\theta_{1}$ to each other, the magnitude of their resultant is $\sqrt{3\left({P}^{2}+{Q}^{2}\right)}$, when they act at an angle $\theta_{2}$, the magnitude of their resultant becomes $\sqrt{2\left({P}^{2}+{Q}^{2}\right)}$. This is possible only when $\theta_{1}<\theta_{2}$.
Statement $II :$ In the situation given above. $\theta_{1}=60^{\circ} \text { and } \theta_{2}=90^{\circ}$ In the light of the above statements, choose the most appropriate answer from the options given below
If the sum of two unit vectors is a unit vector, then magnitude of difference is
If two vectors $\vec{A}$ and $\vec{B}$ having equal magnitude $\mathrm{R}$ are inclined at an angle $\theta$, then
$\overrightarrow A = 2\hat i + \hat j,\,B = 3\hat j - \hat k$ and $\overrightarrow C = 6\hat i - 2\hat k$.Value of $\overrightarrow A - 2\overrightarrow B + 3\overrightarrow C $ would be