Question

Acest exercițiu.Vă mulțumesc!​

Answer 1

$f_1(x)=x$

$f_2(x)=0$

$f_3(x)=2x$

$f_4(x)=\lfloor x/2 \rfloor$ unde

$\lfloor x \rfloor:=\max\left\{k\in\mathbb{Z}:\: k\le x\right\}.$