Respuesta :

sqdancefan
Your supposition requires that

[tex]3\leq \dfrac{f(5)-f(1)}{5-1} \leq 4\\\\12 \leq (f(5)-f(1)) \leq 16[/tex]

The minimum possible value of f(5)-f(1) is 12.
The maximum possible value of f(5)-f(1) is 16.