Exercício Resolvido de Inequações
c)
\( -x^{2}+4x-4<0 \)
\[
\begin{gathered}
-x^{2}+4x-4=0\\[5pt]
\Delta=b^{2}-4ac=4^{2}-4.(-1).(-4)=16-16=0\\[5pt]
t=\frac{-b\pm\sqrt{\Delta \;}}{2a}=\frac{-4\pm\sqrt{0\;}}{2.(-1)}=\frac{-4}{-2}\\[5pt]
x=2
\end{gathered}
\]
\[ \bbox[#FFCCCC,10px]
{V=\mathbb{R}-\{2\}}
\]