Find a.(b x c), if a=2i+j+3k, b=-i+2j+k and c=3i+tj+2k - Mathematics

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Find `veca.(vecbxxvecc), " if " veca=2hati+hatj+3hatk, vecb=-hati+2hatj+hatk  " and " vecc=3hati+hatj+2hatk`

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Solution

Here `veca=2hati+hatj+3hatk, vecb=-hati+2hatj+hatk and vecc=3hati+hatj+2hatk`

`veca.(vecbxxvecc)`

`(vecbxxvecc)=|[hati,hatj,hatk],[-1,2,1],[3,1,2]|=3hati+5hatj-7hatk`

Now `veca.(vecbxxvecc)=(2hati+hatj+3hatk)(3hati+5hatj-7hatk)`

`=veca.(vecbxxvecc)=6+ 5−21=−10`

Concept: Vectors Examples and Solutions
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2013-2014 (March) All India Set 1

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