Answer:
1) 2
2) 4
3) 8
Step-by-step explanation:
You must apply the following formula:
[tex]\frac{f(x_2)-f(x_1)}{x_2-x_1}[/tex]
Substitute value, then you obtain:
x=1 and x=2
[tex]\frac{4-2}{2-1}=2[/tex]
x=2 and x=3
[tex]\frac{8-4}{3-2}=4[/tex]
x=3 and x=4
[tex]\frac{16-8}{4-3}=8[/tex]
