Question

what is 3 icap .4jcap

Answer 1

a= 1i + 2j

b= 3i + 4i= 7i

Dot product

= a.b = (1i +2j) (7i)

=> a.b = 1.7 (i.i) + 2.7 (i.j)

Since i.i= 1 and i.j=0

=> a.b = 7*1 + 14*0

=> a.b = 7

Hope this answered your question.