Answer:
The answer is -2i,2i,7,-7.
Explanation:
It is obvious that if -2i is a zero of the function, 2i is also zero of the function. There for (x^2+4) is a factor of the function. If we divide the function to (x^2+4) we will find other factor of the function.

x^2-49 is the other factor of the function. Therefore, +7 and -7 are the other zeros of the function.