(i) का परिणाम `=sqrt(A_(x)^(2)+A_(y)^(2))=sqrt((3)^(2)+(4)^(2))=5`.
(ii) `vecA * vecB = (3hati + 4hatj) * (12hati - 5hatj)`
`= 36hati * hati - 15hati * hatj * hati - 20hatj * hatj`.
परन्तु `hati * hati = hatj * hatj =1` तथा `hati * hatj = hatj * hati = 0`.
`therefore vecA * vecB = 36 -0+0-20 =16.`