jika f(x) invers dari g(x)=x^3+1 maka f(28)=... A.2 B.2akar2 C.2akar3 D.3 E.3akar2

Materi Invers fungsi

g(x) = x^3 + 1
Misal g(x) = y,
y = x^3 + 1
akar^3 (y-1) = x
akar^3 (x-1) = f(x) << invers g(x)
Berarti
f(28) = akar^3 (28-1) = akar^3 27 = 3 (D)