应该是:|f(x)|≤|g(x)|吧?,若是这样的条件,解法如下:
g(x)=2x²-4x-16
=2(x-1)²-18
2x²-4x-16=0
x²-2x-8=0
(x+2)(x-4)=0
x1=-2 x2=4
∵|f(x)|≤|g(x)|
∴f(x)=x²+ax+b
=(x+2)(x-4)
=x²-2x-8
=(x-1)²-9
∴a=-2 b=-8
应该是:|f(x)|≤|g(x)|吧?,若是这样的条件,解法如下:
g(x)=2x²-4x-16
=2(x-1)²-18
2x²-4x-16=0
x²-2x-8=0
(x+2)(x-4)=0
x1=-2 x2=4
∵|f(x)|≤|g(x)|
∴f(x)=x²+ax+b
=(x+2)(x-4)
=x²-2x-8
=(x-1)²-9
∴a=-2 b=-8