函数f(x)=log2[(a-1)x2+(a-1)x+1/2]若f(x)值域

问题描述:

函数f(x)=log2[(a-1)x2+(a-1)x+1/2]若f(x)值域
函数f(x)=log2[(a-1)x2+(a-1)x+1/2]
1.若f(x)值域为R,求a取值范围.
2.若函数值域为[-2,正无穷],求实数a的取值集合.

楼上肯定错了
1.应该是(a-1)^2-4*(a-1)*0.5=(a-1)(a-3)