ESERCIZIO 1

a) $\displaystyle A=\{x\in \mathbb{N} \mid x=3n+1, n=1,2,3,4,5\}$

b) $\displaystyle B=\{x\in \mathbb{N} \mid x=3n^2, n=1,2,3,4,5\}$

SOLUZIONE

a) $\displaystyle A=\{ 4,7,10,13,16\}$

b) $\displaystyle B=\{ 3,12, 27,48,75\}$

ESERCIZIO 2

Rappresenta per caratteristica i seguenti insiemi:

a) $\displaystyle A=\{ 4,9,16,25,36\}$

b) $\displaystyle B=\{ 2,5, 10,17,26\}$

c) $\displaystyle C=\{ 0, 7, 26, 63, 124\}$

SOLUZIONE

a) $\displaystyle A=\{x\in \mathbb{N} \mid x=n^2, n=2,3,4,5,6\}$

b) $\displaystyle B=\{x\in \mathbb{N} \mid x=n^2+1, n=1,2,3,4,5\}$

c) $\displaystyle C=\{x\in \mathbb{N} \mid x=n^3-1, n=1,2,3,4,5\}$