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The condition for equations `vecrxxveca = vecb and vecr xx vecc = vecd` to be consistent isA. `vecb.vecc=veca.vecd`B. `veca.vecb=vecc.vecd`C. `vecb.vecc+veca.vecd=0`D. `veca.vecb+vecc.vecd=0` |
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Answer» Correct Answer - c ` vecr xx veca = vecb ` ` or vecd xx ( vecr xx veca)= vecd xx vecb` `or (veca .vecd) vecr - (vecd.vecr) veca= vecd xx vecb` ` vecr xx vecc = vecd` ` or vecb xx ( vecr xx vecc) = vecb xx vecd` ` or (vecb .vecc) vecr - (vecb.vecr) vecc = vecb xx vecd` Adding (i) and (ii) , we get ` ( veca. vecd + vecb . vecc) vecr- (vecd.vecr) veca - (vecb.vecr) vecc ` Now `vecr.vecd = 0 and vecb.vecr=0 as vecd and vecr` as `vecb and vecr` are mutually perpendicular. Hence ` ( vecb.vecc + veca.vecd)vecr = vec0` |
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