已知抛物线y=x²-(k+2)x+9的顶点在坐标轴上,求k

已知抛物线y=x²-(k+2)x+9的顶点在坐标轴上,求k
已知抛物线y=x²-(k+2)x+9的顶点在坐标轴上,求k

已知抛物线y=x²-(k+2)x+9的顶点在坐标轴上,求k
y=x²-(k+2)x+9=[x-(k+2)/2]²+9-(k+2)^2/4
9-(k+2)^2/4=0
(k+2)^2=36
k=4或k=-8