Answer
$\{-3,4,1+i,1-i \}$
Work Step by Step
Step 1. Given $x=1+i$ as a zero, we can identify $x=1-i$ is also a zero.
Step 2. Use synthetic divisions as shown in the figure to get a quotient as $x^2-x-12$
Step 3. Solve $x^2-x-12=0$ or $(x+3)(x-4)=0$ to get $x=-3,4$ as zeros.
Step 4. The zeros are $\{-3,4,1+i,1-i \}$
