Question

Y = - x² + 4x - 5 resoluçao A) ( -1 , 10 ) B) ( 0 , 5) C) ( 1, -2 ) D) ( 3 , -2 ) E) ( 0 , -4 )

Answer 1

y = -x² +4x -5 .(-1)
y = x² -4x +5

x² -4x +5 = 0

Δ = b² -4ac
Δ = (-4)² -4 . 1 . 5
Δ = 16 -20
Δ = -4

Δ ≥ 0

E) (0 , -4)