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Question
The 2 vectors `hat"j" + hat"k"` and `3hat"i" - hat"j" + 4hat"k"` represents the two sides AB and AC, respectively of a ∆ABC. The length of the median through A is ______.
Options
`sqrt(34)/2`
`sqrt(48)/2`
`sqrt(18)`
None of these
Solution
The 2 vectors `hat"j" + hat"k"` and `3hat"i" - hat"j" + 4hat"k"` represents the two sides AB and AC, respectively of a ∆ABC. The length of the median through A is `sqrt(34)/2`.
Explanation:
Median `vec"AD"` is given by
`|vec"AD"| = 1/2 |3hat"i" + hat"j" + 5hat"k"|`
= `sqrt(34)/2`
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