Answer:
-1 ± i√3
Explanation:
You can rearrange the expression to vertex form:
x^2 +2x +1 +3
(x +1)^2 +3
You want to find the values of x that make this zero:
(x +1)^2 +3 = 0 . . . . . . . set the expression equal to zero
(x +1)^2 = -3 . . . . . . . . . subtract 3 to get the square alone
x +1 = ±√(-3) = ±i√3 . . .take the square root
x = -1 ±i√3 . . . . . . . . . . subtract 1
The zeros are the complex numbers -1+i√3 and -1-i√3.