• Matéria: Matemática
  • Autor: greenforestclix
  • Perguntado 9 anos atrás

QUESTÃO 2


O vértice da parábola y= 2x²- 4x + 5 é o ponto:





(1,3)


(-1,-3)


(-1,11)


(4,3)


(2,5)

Respostas

respondido por: LuanaSC8
2
y= 2x^2- 4x + 5\to \\\\2x^2- 4x + 5=0\\\\ a=2;\ b=-4;\ c=5\\\\\\  x_v= \dfrac{-b}{2a}\to ~~ x_v= \dfrac{-(-4)}{2.2}\to ~~x_v= \dfrac{4}{4}\to ~~\boxed{x_v=1}  \\\\\\\\ \Delta=b^2-4ac\to \Delta=(-4)^2-4.2.5\to \Delta=16-40\to \boxed{\Delta=-24}\\\\\\ y_v= \dfrac{-\Delta}{4a}\to ~~ y_v= \dfrac{-(-24)}{4.2}\to ~~ y_v= \dfrac{24}{8}\to ~~ \boxed{y_v=3}\\\\\\\\\\ \boxed{\boxed{V=\{1~;~3\}}}



R.: Primeira alternativa.
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