Question 1068323
the zeros are i and -i 3i and -3i, because complex roots appear in conjugate pairs.
(x^2+1) and (x^2+9) will give roots +/- i and 3i respectively.
the polynomial is a(x^4+10x^2+9)
f(-1)=20
a(1+10+9)=20
so a=1
x^4+10x^2+9 is polynomial
{{{graph(300,300,-10,10,-100,300,x^4+10x^2+9)}}}