1.抛物线顶点为(2,-3),y = a(x - 2)² - 3
经过原点:0 = 4a -3,a = 3/4
y = (3/4)(x - 2)² - 3 = (3/4)(x² - 4x)
对称轴x = 2,与x轴的另一个交点的坐标:(2+2,0)即 (4,0)
2.整点:
x = 1,y = -4/9,整点:(1,-1),(1,-2),2个
x = 2,y = -3,整点:(2,-1),(2,-2),2个
x = 3,y = -4/9,整点:(3,-1),(3,-2),2个
共6个