Strasznie niewyrazne znaki, wiec w przykladzie b zrobie na 2 sposoby.
[tex]a) \\\frac{2+x}{4x^2}\\4x^2\neq 0\\x^2\neq 0\\x\neq 0\\D\in R / \{0\}\\\\b) \\\frac{3x^2}{x^2+3x+2}\\\\x^2+3x+2\neq 0\\\Delta=3^2-4*1*2=9-8=1\\x_1=\frac{-3-1}{2}=\frac{-4}2=-2\\x_2=\frac{-3+1}2=\frac{-2}2=-1\\\\D\in R / \{-2, -1\}\\\\\frac{3x^2}{x^2-3x-2}\\\\x^2-3x-2 \neq 0\\\Delta=(-3)^2-4*1*(-2)\\\Delta=9+8=17\\x_1=\frac{3-\sqrt{17}}2\\x_2=\frac{3+\sqrt{17}}2\\\\D\in R/\{\frac{3-\sqrt{17}}2; \frac{3+\sqrt{17}}2\}[/tex]
