Question

calcule o vértice das funções do 2° grau. A) f (x)=x² -5x +6
B) f(x)= 2x² -8x +3
C) f(x)= -x² -4x +4​

Answer 1

Resposta:

Explicação passo-a-passo:

A)

X do vértice:

$x_{v}=\frac{-b}{2a}\\\\x_{v}=\frac{-(-5)}{2*1}\\\\x_{v}=\frac{5}{2}$

Y do Vértice:

$f(x)=x^2-5x+6\\\\f(\frac{5}{2} )=(\frac{5}{2})}^2-5(\frac{5}{2})+6\\\\f(\frac{5}{2}) =-\frac{1}{4} = y_{v}$

B)

X do Vértice:

$x_{v} =\frac{-b}{2a}\\\\x_{v} =\frac{8}{4}\\\\x_{v} =2$

Y do Vértice:

$f(2)=2(2)^2-8(2)+3\\f(2)=-5=y_{v}$

C)

X do Vértice:

$x_{v} =\frac{-b}{2a}\\\\x_{v} =\frac{4}{-2}\\\\x_{v} =-2$

Y do vértice:

$f(-2)=-(-2)^2-4(-2)+4\\f(-2)=8=y_{v}$