Question

Resolva as inequações do segundo grau simultaneamente, realizando o estudo do sinal

Answer 1

— 8 ≤ x² — 2x — 8 ≤ 0

{ x² — 2x — 8 ≥ — 8

{ x² — 2x — 8 ≤ 0

{ x² — 2x ≥ 0

{ x² — 2x — 8 ≤ 0

{ x ( x — 2 ) ≥ 0

{ ( x + 2 )( x — 4 ) ≤ 0

{ S1 : x€ ( — ∞ , 0 ] U [ 2 , + ∞ )

{ S2 : x€ [ — 2 , 4 ]

S1 Π S2 : x € [ — 2 , 0 ] U [ 2 , 4 ]

x€ [ — 2 , 0 ] U [ 2 , 4 ] .