Matemática, perguntado por lucaslimarx, 1 ano atrás

1* As seguintes funções são definidas em IR. Verifique quais são as funções quadráticas e identifique em cada uma os valores de a, b e c

A) F(x) = 2x (3x - 1) = 6x² - 2x

B) F(x) = (x + 2) (x - 2) - 4

C) F(x) = (1 + x) (1 - x) + x²

D) F(x) = (x+2)² - x (x + 1) = F(x)


2* Seja F(x) = 2x² - 3x + 1, calcule f(  \sqrt{x} 2/3 )

Soluções para a tarefa

Respondido por Usuário anônimo
5
Bom dia Lucas!

Solução!

A)\\\\\
2x(3x-1)=6 x^{2} -2x\\\\\
6 x^{2} -2x=6 x^{2} -2x\\\\\\
6 x^{2} -6 x^{2} -2x-2x=0\\\\\\
0=0~~N\~ao~~e\´~~uma~~func\~ao~~quadratica


B)\\\\\\\\\
(x+2).(x-2)=4\\\\\
 x^{2} +2x-2x-4-4=0\\\\\
 x^{2} -8=0\\\\\\\\\
E\´~~uma~~func\~ao~~quadratica\\\\\\\\

Coeficientes!~~a=1~~b=0~~c=-8


C)\\\\\\ (1+x).(1-x)+ x^{2} =0\\\\\\ 1-x+x- x^{2} + x^{2} =0\\\\\ N\~ao~~e\´~~uma~~func\~ao~~quadratica!




D)\\\\\
(x+2)^{2}-x(x+1)=0\\\\\
 x^{2} +4x+4- x^{2}-x=0\\\\\\
4x+4=0 \\\\\\
N\~ao~~e\´~~uma~~func\~ao~~quadratica!

E)\\\\\\
f(x)=2 x^{2} +3x+1\\\\\\\\\
f\bigg( \dfrac{ \sqrt{ x^{2} } }{3}\bigg) =2 x^{2} +3x+1\\\\\\\\
f\bigg( \dfrac{ x }{3}\bigg)=2\bigg( \dfrac{ x }{3}\bigg)^{2}+3\bigg( \dfrac{ x }{3}\bigg)+1\\\\\\ 

f\bigg( \dfrac{ x }{3}\bigg)= \bigg(\dfrac{ 2 x^{2}  }{9}\bigg)+\bigg( \dfrac{ 3x }{3}\bigg)+1\\\\\\

f\bigg( \dfrac{ x }{3}\bigg)= \dfrac{ 2 x^{2}  }{9}+x+1\\\\\\

Bom dia!
Bons estudos!

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