The factored form is, x =3i and x = -3i
Given:
The objective is to write x^2+9 in factored form.
The factored form can be written as,
[tex]\begin{gathered} x^2+9=0 \\ x^2=-9 \\ x=\sqrt[]{-9} \\ x=\pm3i \end{gathered}[/tex]Here, i stands for imaginary term due the square root of (-1).
Hence, the factored form is, x =3i and x = -3i.