Question

As coordenadas do vértice v da parábola que representa a função f(x)=(x-3)2-1 é:

Answer 1

f(x) = (x-3)² - 1
x² - 2x.3 + 3² - 1 = 0
x² - 6x + 9 - 1 = 0

x² - 6x + 8
∆ = b² - 4ac
∆ = (-6)² - 4.1.8
∆ = 36 - 32
∆ = 4

x = ( -b +-√∆)/2a

x = ( 6+-√4)2

x = (6+-2)2

x' = (6+2)/2 = 8/2 = 4

x" = (6-2)/2 = 4/2 = 2

x' = 4
x" = 2