Tentukan nilai m agar f(x)=x²(m+2)x+4definit positif

D < 0
b² - 4ac < 0
(m+2)² - 4(1)(4) < 0
m² + 4m + 4 - 16 < 0
m² + 4m - 12 < 0
(m + 6)(m - 4) < 0
-6 < m < 4