Resposta :
Vamos là.
f(x) = x² - 4x + 3
a = 1, b = -4, c = 3
vértice
Vx = -b/2a = 4/2 = 2
Vy = f(2) = 4 - 8 + 3 = -1
V(2, -1) (C)

Vamos là.
f(x) = x² - 4x + 3
a = 1, b = -4, c = 3
vértice
Vx = -b/2a = 4/2 = 2
Vy = f(2) = 4 - 8 + 3 = -1
V(2, -1) (C)