函数f(x)=log3(ax^2-x+a)有零点, - 知识问答

函数f(x)=log3(ax^2-x+a)有零点,求a的取值范围.

1个回答

log3(ax^2-x+a) =0
ax^2-x+a = 1
ax^2-x +(a-1) =0
△≥ 0
=> 1-4a(a-1)≥0
4a^2-4a-1≤0
(1-√2)/ 2 ≤ a ≤(1+√2)/ 2

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