题目内容
(本题满分14分)
已知函数f(x)=ax2+a2x+2b-a3,当x∈(-2,6)时,其值为正,而当x∈(-∞,-2)∪(6,+∞)时,其值为负.
(Ⅰ)求实数a,b的值及函数f(x)的表达式;
(Ⅱ)设F(x)=-
f(x)+4(k+1)x+2(6k-1),问k取何值时,函数F(x)的值恒为负值?
已知函数f(x)=ax2+a2x+2b-a3,当x∈(-2,6)时,其值为正,而当x∈(-∞,-2)∪(6,+∞)时,其值为负.
(Ⅰ)求实数a,b的值及函数f(x)的表达式;
(Ⅱ)设F(x)=-
![](http://thumb.1010pic.com/pic2/upload/papers/20140823/20140823193708757395.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140823/2014082319370878821335.jpg)
略
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目