bantu jawab................

f(x) = x² - 1

f(-3) = (-3)² - 1 = 9 - 1 = 8
f(-1) = (-1)² - 1 = 1 - 1 = 0
f(0) = (0)² - 1 = 0 - 1 = -1
f(2) = (2)² - 1 = 4 - 1 = 3
f(3) = (3)² - 1 = 9 - 1 = 8

(* karena f(a) = f(-a) maka range fungsinya di mulai dari f(0) sampai f(3)
Rf = {f(0) ≤ y ≤ f(3) , y ∈ R}
    = {-1 ≤ y ≤ 8 , y ∈ R}


f(a) = a² - 1
a² - 1 = 3
a² = 4
a = -2  atau  a = 2