They are made by 1. 4 is made by 2, 8 is made by 2 and 4, 6 is made by 2 and 3.
The answer to this questuon is 2
It is 4 because 3 times 4 equals 12
Function g takes 4 as input and return 2 as output
f takes input 2 and returns output 4
from the graph
g(4)=2
f(2)=4