If you observer the value of x=0 and x=1, you can conclude that every 1 value of x increased, the f(x) will be increased by 0.5. The graph function should be:
f(x)= x/2
A positive difference means that the value should be always positive. To find 3 the positive difference of f(x) with 3 values of x apart, let use x=0 and x=0+3= 3. The difference would be:
f(x+3) - f(x)
f(3)- f(0)=
1.5 - 0= 1.5
The answer would be: 1.5
