Jika f(x+1) = f(x) +2x + 2 dan f(1) =1, tentukan nilai f(4).

f(x+1) = f(x) + 2x + 2

f(1+1) = f(1) + 2×1 + 2
f(2) = 1 + 2 + 2
f(2) = 5

f(2+1) = f(2) + 2×2 + 2
f(3) = 5 + 4 + 2
f(3) = 11

f(3+1) = f(3) + 2×3 + 2
f(4) = 11 + 6 + 2
f(4) = 19

smga mmbantu