Question

alguém me ajuda a responde essas questão , e urgente

Answer 1

OLá Duda,

vou fazer algumas, pra vc resolver as outras, mas se tiver dificuldade me chame ;D ^^

$y=2x^2-3x+1$
$2x^2-3x+1=0$

$a=2$
$b=-3$
$c=1$

$\Delta=b^2-4ac$
$\Delta=(-3)^2-4\cdot2\cdot1$
$\Delta=9-8$
$\Delta=1$
$x= \dfrac{-b\pm \sqrt{\Delta} }{2a}= \dfrac{-(-3)\pm \sqrt{1} }{2\cdot1}= \dfrac{3\pm1}{2}$

$x'= \dfrac{3-1}{2}= \dfrac{2}{2}=1$

$x''= \dfrac{3+1}{2}= \dfrac{4}{2}=2$


$x'=1~~e~~x''=2$

___________

$y=4x-x^2$
$-x^2+4x=0$
$-x(x-4)=0$

$-x=0$
$x'=0$


$x-4=0$
$x''=4$

___________

$y=9x^2-1$
$9x^2-1=0$
$9x^2=1$
$x^2= \dfrac{1}{9}$
$x= \pm \sqrt{ \dfrac{1}{9} }$

$x'= \sqrt{ \dfrac{1}{9} }~~e~~x''= -\sqrt{ \dfrac{1}{9} }$

___________

$y=x^2+2$
$x^2+2=0$
$x^2=-2$
$x=\pm \sqrt{-2}~~(n\~ao~existem~raizes~reais)$

___________


$y=3x^2$
$3x^2=0$
$x^2= \dfrac{0}{3}$
$x^2=0$
$x=\pm \sqrt{0}$
$x'=x''=0$


Tenha ótimos estudos ;D