2 replies to this topic

[thangnhoc9x]

xet tat ca cac ham so bac 2 y=a$x^{2}$+bx+c voi a<b va y>0 voi moi x. cm
$\frac{a+b+c}{b-a}$> hoac=3

[anhbz1610]

$Do y>0 suy ra delta <= 0 suy ra b2≤4ac≤(4a+c)2/4⇔2b≤4a+c⇒a+b+cb−a≥3$

[anhbz1610]

de vay cung hoi