Berapakah daerah asal jika berfungsi f:x->x+1 dengan daerah asal {2,4,6,8} sertakan cara

f(x) = x + 1
f(2) = 2 + 1
= 3
f(4) = 4 + 1
= 5
f(6) = 6 + 1
= 7
f(8) = 8 + 1
= 9
daerah hasil = {3,5,7,9}