How do you write a polynomial function of least degree with integral coefficients that has the given zeroes 6, 2i?

1 Answer
Jul 17, 2016

f(x)=x36x2+4x24

Explanation:

If a polynomial has Real coefficients then any non-Real zeros will occur in Complex conjugate pairs. So if 2i is a zero, then so is 2i.

Hence our polynomial function can be written:

f(x)=(x6)(x2i)(x+2i)

=(x6)(x2+4)

=x36x2+4x24

Any polynomial in x with these zeros will be a multiple (scalar or polynomial) of this f(x)