Jika f(n) = f(n – 1) + n + 1 dan f(-2) = 1,
tentukan nilai f(-4).
Jawaban:
f(n) = f(n – 1) + n + 1
f(-2) = 1
⇔ f(–2 – 1) + (–2) + 1 = 1
⇔ f(–3) – 1 = 1
⇔ f(–3) = 2
⇔ f(–3 – 1) + (–3) + 1 = 2
⇔ f(–4) – 2 = 2
⇔ f(–4) = 4
Jadi, nilai f(–4) adalah 4