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Question
If the position vector of a point (−4, −3) be \[\vec{a,}\] find \[\left| \vec{a} \right|\]
Solution
Given a point \[\left( - 4, - 3 \right)\] such that its position vector \[\vec{a}\] is given by \[\vec{a} = - 4\hat{i}- 3 \hat{j}\]
Then,
\[\left| \vec{a} \right| = \sqrt{\left( - 4 \right)^2 + \left( - 3 \right)^2} = \sqrt{16 + 9} = \sqrt{25} = 5\]
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