Lista de exercícios do ensino médio para impressão
Solve the following inequalities:
a)
$\,(1\,-\,4x^2)\centerdot(2x^2\,+\,3)\,\gt\,0\,$
b)
$\,(2x^2\,-\,7x\,+\,6)\centerdot(2x^2\,-\,7x\,+\,5)\,\leqslant\,0\,$
c)
$\,(x^2\,-\,x\,-\,6)\centerdot(-x^2\,+\,2x\,-1)\,\gt\,0\,$
d)
$\,(x^2\,+\,x\,-\,6)\centerdot(-x^2\,-2x\,+\,3)\,\geqslant\,0\,$
e)
$\,x^3\,-\,2x^2\,-\,x\,+\,2\,\gt\,0\,$
f)
$\,2x^3\,-\,6x^2\,+\,x\,-\,3\,\leqslant\,0\,$

 



answer:
a)
$\,\mathbb{S}\,=\,\lbrace x\,\in\,{\rm I\!R}\;|\;-\frac{3}{2}\,\lt\,x\,\lt\,-\frac{1}{2}\phantom{X}{\text or}\phantom{X}0\,\lt\,x\,\lt\,\frac{1}{2}\rbrace\;$
b)
$\,\mathbb{S}\,=\,\lbrace x\,\in\,{\rm I\!R}\;|\;1\,\leqslant\,x\,\leqslant\,\frac{3}{2}\phantom{X}{\text or}\phantom{X}2\,\leqslant\,x\,\leqslant\,\frac{5}{2}\rbrace\;$
c)
$\,\mathbb{S}\,=\,\lbrace x\,\in\,{\rm I\!R}\;|\;-2\,\lt\,x\,\lt\,3\phantom{X}{\text e}\phantom{X}x\,\ne\,1\rbrace\;$
d)
$\,\mathbb{S}\,=\,\lbrace x\,\in\,{\rm I\!R}\;|\;x\,=\,-3\phantom{X}{\text or}\phantom{X}1\,\leqslant\,x\,\leqslant\,2\rbrace\;$
e)
$\,\mathbb{S}\,=\,\lbrace x\,\in\,{\rm I\!R}\;|\;-1\,\lt\,x\,\lt\,1\phantom{X}{\text or}\phantom{X}x\,\gt\,2\rbrace\;$
e)
$\,\mathbb{S}\,=\,\lbrace x\,\in\,{\rm I\!R}\;|\;x\,\leqslant\,3\rbrace\;$

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Other math tests: quadratic inequalities