Arturo O. answered 05/14/20
Experienced Physics Teacher for Physics Tutoring
(a)
The complex conjugate of a complex zero must also be a zero, so the 4 zeros are
7
-7
2i
-2i
f(x) = 1(x - 7)(x + 7)(x - 2i)(x + 2i)
(b)
I will get you started.
(x - 7)(x + 7) = x2 - 49
(x - 2i)(x + 2i) = x2 + 4
f(x) = (x2 - 49)(x2 + 4)
You finish from here.