Answer:
f(x) = x² - 9
Explanation:
Given x = a is a zero of the polynomial f(x) then (x - a) is a factor
Given zeros are x = 3 and x = - 3, then corresponding factors are
(x - 3) and (x - (- 3) ), that is
(x - 3) and (x + 3)
The function is then the product of the factors, that is
f(x) = (x - 3)(x + 3) ← expand using FOIL
f(x) = x² - 9