Question

y=x²-4x-5 vertice da função

Answer 1

a = 1
b = - 4
c = - 5

∆ = b^2 - 4.a.c
∆ = (-4)^2 - 4.1.(-5)
∆ = 16+20
∆ = 36

X = -b+/- √∆ /2.a
X = -(-4)+/-√36/2.1
X = 4+/-6/2

X1=4+6/2
X1 = 10/2
X1 = 5

X2 = 4 - 6/ 2
X2 = -2 / 2
X2 = - 1