![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
Explanation :
\If a polynomial has an imaginary zero, then its complex conjugate is also a zero of the polynomial.
\Therefore, any polynomial that has one imaginary zero has at least two imaginary zeros.
\![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
Therefore, any polynomial that has one imaginary zero has at least two imaginary zeros.