抛物线y=x²-kx+k,当k=_______时,顶点在x轴上;当k=______时,抛物线过原点,

抛物线y=x²-kx+k,当k=_______时,顶点在x轴上;当k=______时,抛物线过原点,
抛物线y=x²-kx+k,当k=_______时,顶点在x轴上;当k=______时,抛物线过原点,

抛物线y=x²-kx+k,当k=_______时,顶点在x轴上;当k=______时,抛物线过原点,
顶点在x轴
则和x轴是一个公共点
所以△=k²-4k=0
k(k-4)+0
所以k=0,k=4
过原点则x=0时y=0
所以0=0-0+k
k=0