The resultant of $(\overrightarrow{\mathbf{p}} - 2\overrightarrow{\mathbf{q}})$ where. $\overrightarrow{\mathbf{p}} = 7\widehat{\dot{\mathbf{i}}} - 2\widehat{\dot{\mathbf{j}}} + 3\widehat{\dot{\mathbf{k}}}$ and $\overrightarrow{\mathbf{q}} = 3\widehat{\dot{\mathbf{i}}} + \widehat{\dot{\mathbf{j}}} + 5\widehat{\dot{\mathbf{k}}}$ is

Question

Dr. Abubacker · Accepted Answer

(d)
$	herefore\ \ \overrightarrow{\mathbf{p}} - 2\ \overrightarrow{\mathbf{q}} = 7\widehat{\dot{\mathbf{i}}} - 2\widehat{\dot{\mathbf{j}}} + 3\widehat{\mathbf{k}} - 2\left( 3\widehat{\dot{\mathbf{i}}} + \widehat{\dot{\mathbf{j}}} + 5\widehat{\mathbf{k}} ight)$
$= \widehat{\dot{\mathbf{i}}} - 4\widehat{\dot{\mathbf{j}}} - 7\widehat{\mathbf{k}}$
$\Longrightarrow \left| \overrightarrow{\mathbf{p}} - 2\overrightarrow{\mathbf{q}} ight| = \sqrt{1^{2} + {( - 4)}^{2} + {( - 7)}^{2}} = \sqrt{66}$

Explanation

Reviewed by Dr. Abubacker

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