Question

7- Determine as coordenadas do vértice da parábola, da função f(x)= -x²+2x+8:

a) (1,7)
b) (-2,4)
c) (7,1)
d) (0,-7)

Answer 1

Resposta:

a) (1,7)

Explicação passo a passo:

Vamos usar (Xvertice) e (Yvertice)

$Para(X)\\\\ x_{V} = -\frac{b}{2*a} \\\\\\ x_{V} = -\frac{2}{2*-1} \\\\ x_{V} = \frac{-2}{-2} = 1\\\\para(Y)\\\\ Y_{V} = -\frac{DELTA}{4*a} \\\\ Y_{V} = -\frac{b^{2}-4*a*c }{4*a} \\\\\ Y_{V} = -\frac{2^{2}-4*-1*8 }{4*-1}\\\\Y_{V} = -\frac{4+32 }{-4}\\\\Y_{V} = -\frac{28 }{-4}\\\\Y_{V} = -(-7)=7$