Question

C(-3;1) D(9;6) длину вектора

Answer 1

$AB = sqrt{(9-(-3)) ^{2} +(6-1) ^{2} ) } = sqrt{(9+3) ^{2}+(6-1) ^{2} } = sqrt{12 ^{2} +5 ^{2} }=$$sqrt{144+25}= sqrt{169}=13$