VECTORS - 1

If u = 6i + 2j and v = 3i + 10j find 7u + 3v

solution

= 7u + 3v

= 7(6i + 2j) + 3(3i + 10j)

= 42i + 14j + 9i + 30j

= (12i + 30i) + (14j + 30j)

= 42i + 44j

Hence 7u + 3v = 42i + 44j

TRY THIS..................

NECTA 2001 QN. 12a (i)

If u = 4i + 3j and v = 2i + 4j;  find 2u + 3v.