[tex]m^3+3m^2-9m\geq 0\\
m(m^2+3m-9)\geq0\\
\text{Sa aflam radacinile ecuatiei de gradul 2.}\\
m^2+3m-9=0\\
\Delta=9+36=45\Rightarrow \sqrt{\Delta}=3\sqrt5\\
m_1=\dfrac{-3+3\sqrt5}{2},m_2=\dfrac{-3-3\sqrt5}{2}\\
\text{Facem un tabel de semn:} [/tex]
[tex] ~~~~~~~~~~~~~~~~~~ | ~~~~\dfrac{-3-3\sqrt5}{2}~~~~~~~~~~~~~~~0~~~~~~~~~~~~~~~~~\dfrac{-3+3\sqrt5}{2}\\
~~~~~m~~~~~~~~~~|-~~~~~-~~~~~~~~~-~~~~~~~~0~~~~~+~~~~~~~+~~~~~~~+\\
m^2+3m-9|++~~~~0~~~~-~~~~~~~~~~~~-~~~~~~~-~~~~~~~~~~~~~0~~~+~~~+\\
~~~~~~~~~~~~~~~~~~|-~~~~~~0~~~~~~~~~+~~~~~~~~~0~~~~~~~~~~~-~~~~~~~~~0~~~~~~~~~~~~+\\
S:m\in \left[\dfrac{-3-3\sqrt5}{2},0\right]\cup \left[\dfrac{-3+3\sqrt5}{2},\infty\left)[/tex]
