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
