[tex]6)\quad f:\mathbb_{R} \rightarrow \mathbb_{R}, $ $\quad f(x) = (m^2-2)x-3, \quad $strict descrescatoare. \\ \\ $f(x)$ -$ $ $ $str. descr. atunci cand $a\ \textless \ 0 \Rightarrow m^2-2\ \textless \ 0 \Rightarrow m^2\ \textless \ 2\Big|\sqrt{\boxed{}} \Rightarrow \\ \\ \Rightarrow \sqrt{m^2}\ \textless \ \sqrt 2 \Rightarrow |m|\ \textless \ \sqrt2 \Rightarrow -\sqrt2\ \textless \ m\ \textless \ \sqrt2 \Rightarrow \boxed{m \in (-\sqrt2,\sqrt2)}[/tex]
