Question

O vértice da função y = x2 – 2x - 1é igual a:

A(1,3)

B(3,1)

C(1,-2)

D(2,-1)

Answer 1

∆ = b²-4ac = (-2)² -4.1.(-1)= 4 +4= 8

xv= -b/2a = -(-2)/2.1= 2/2 = 1

yv= -∆/4a = -8/4.1= -8/4 = -2

===> V(1, -2)