Răspuns :
Răspuns:
Explicație pas cu pas:
3/(2n + 1)
n € N
2n + 1 € D3
2n + 1 € { 1 , 3 } | - 1
2n € { 0 , 2 } | : 2
n € { 0 , 1 }
[tex]\displaystyle\bf\\ \frac{3}{2n+1}\in N~~si~~n\in N\\\\2n-1 \in D_3\\\\D_3=\{1;~3\}\\\\2n+1=1\\2n=1-1\\2n=0\\\boxed{\bf~n=0}\\\\2n+1=3\\2n=3-1\\2n=2\\\\n=\frac{2}{2}\\\\\boxed{\bf~n=1}\\\\\boxed{\boxed{\bf~n\in\{0;~1\}}}[/tex]
