Question

Find the polynomial of lowest degree w/ only real coefficient and having the given zeros 2+i, 3

Answer 1

if 2+i is one zero then 2-i is also one of the zero
hence reqd polynomial is
(x-3)( x-2-i)(x-2+i)

Answer 2

=(x-3)* ( (x-2)^2 -i^2)
=(x-3)*( (x-2)^2 +1 )
and so on ....