Write the polynomial in standard form

f(x)= (x+2)(x-√3i)(x+√3i)

(x+2)(x-√3i)(x+√3i)

(x-√3i)(x+√3i)
are parts of the 'difference of squares' equation
(x^2-3)

gives you
(x+2)(x^2-3)

distribute
x(x^2-3)+2(x^2-3)
x^3-3x+2x^2-6

x^3+2x^2-3x-6

Just a hint (x-√3i)(x+√3i) = x^2 + 9

Can you take it from here?

f(x) = (x + 2)(x^2 + 3)
f(x) = x^3 + 2x^2 + 3x + 6