Answer:
1. There will be two roots not only one
2.a([tex]x^{2}[/tex] +16) =0
Step-by-step explanation:
Simply assume a quadratic equation [tex]ax^{2} +bx+c[/tex]
Here a,b,c are real independent variables.
As given by student -4i is one of it's root it must satisfy the equation.
-16a +4ib+c=0
b must be zero otherwise either a or c must be imaginary number which is not possible.
So b =0
then, c= 16a
a[tex]x^{2}[/tex]+c=a[tex]x^{2}[/tex]+16a
Quadratic is a([tex]x^{2}[/tex] +16) =0 here a is any real number.