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If a+b+c=0 and |a|=sqrt(37),|b|=3, |c|=4 then the angle between b and c is |
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Answer» `30^(@)` Now, `a+b+c=0` `implies a=-(b+c)` `implies |a|^(2)=|-(b+c)|^(2)` `implies |a|^(2)=|b|^(2)+|c|^(2)+2|b||c| cos theta` `=9+16+24 cos theta` `implies 37=25+24 cos theta` `implies 24 cos theta =12 implies theta = 60^(@)` |
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