抛物线y=4x²-4(k+1)x+4k-1与y轴相交于（x1,0) (x2,0 ) 两点 且0＜x1＜1＜x2＜2 则k的取值范围是

题目

抛物线y=4x²-4(k+1)x+4k-1与y轴相交于（x1,0) (x2,0 ) 两点 且0＜x1＜1＜x2＜2 则k的取值范围是

答案

f(x)=4x²-4(k+1)x+4k-1开口向上
则画图可知
f(0)=4k-1>0,k>1/4
f(1)=4-4k-4+4k-10,kk