Find the zeros of the function f (x) = x2 + 6x + 18.

The 2 is square

To find the number of zeros in the quadratic equation we factorize it as follows:

f (x) = x²+6x+18

solving using completing square methods we obtain:

x^2+6x=-18

c = (b/2a) ^2=9

thus

x²+6x+9=-18+8

x²+6x+9=-9

(x+3) ²=-9

hence

x=-3+/-3i

the roots are:

x=-3+3i or x=-3-3i