Question

Find a polynomial of degree with real coefficients and the following zeros: 4,2-i

Answer 1

when you have real coefficients
and one of root is 4-i another root must be 4+i
so
can you go on
?

Answer 2

like this
suppose one of root is 3+2i
with real coefficient
f(x)=a(x-(3+2i))(x-(3-2i) )
= a(x^2 +(9-(2i)^2- 2x(3+2i+3-2i))
=a(x^2+(9+4)+2x(6))