Question

Sa se determine care din relatiile urmatoare sunt adevarate:
a)$\frac{9}{7} ∈ (-inf,2]$;
b) π (pi) ∈ (3,14;5);
c) $[-(-2)+(-3)^{2}$[-(-2)+(-3)] (nu apartine) (0,2);
h) $(-2)^{2}$ ∈ [-4,0).

Answer 1

[tex]\displaystyle a)~~ \frac{9}{7} \in (-\infty,~2] ~~~\bold{Adevarat}~deoarece:~~ \frac{9}{7} \ \textless \ \frac{14}{7}=2 \\ \\ b)~~\pi \in (3,14;~5) ~~~\bold{Adevarat}~deoarece:~~ \pi = 3,141592... \ \textgreater \ 3,14 \\ \\ c)~~ [-(-2)+(-3)^{2}] [-(-2)+(-3)] \notin (0;~2) \\ ~ [2+9] [2-3] \notin (0;~2) \\ 3 \times (-1) \notin (0;~2) \\ -3 \notin (0;~2) ~~~\bold{Adevarat}~deoarece:~~ -3 \ \textless \ 0 \\ \\ h)~~ (-2)^2 \in [-4;~0) ~~~\bold{FALS}~deoarece:~~ (-2)^2 =4 \ \textgreater \ 0[/tex]

Answer 2

9/7=1,2 ∈(-inf,2]
pi=3,1415...∈(3.14;5)
[-(-2)+(-3)²][-(-2)+(-3)
(2+9)(2-3)=11×-1
-11∉(0,2)
(-2)²=4∉[-4,0)
1.adevarata
2.adevarata
3.adevarata
4.falsa