May be you know it or not a two dimensional vector can be represented by a complex number.Why i have written this statement you will just know when you will see its solution
a = 3i + mj and b = 2i - nj are perpendicular to each other ,so their dot product
will be zero.
j
vector b = 2i - nj and vector c = ni + 8j are parallel to each other.j
mn = 6
so m=6/4i
m=3/2i
m=3i^{4}/2i
m = 3i^{3}/2
m= -3i/2 as(i^{4} =1, i^{3} = -i[/tex][/tex]