Question

一道函数的竞赛题已知二次函数y等于ax^加bx加c和一次函数y等于负bx,其中a,b,c满足a大于b大于c,a加b加c等

Answer 1

y=ax²+bx+c,y=-bx

∵a>b>c,a+b+c=0,b=-a-c

∴a>0,c-a-c ==>2ac/a>-2

{-a-c>c ==>ac/a