y=ax²+bx
=a[x²+bx/a+(b/2a)²]-a×b²/4a²
=a(x+b/2a)²-b²/4a
(1)
顶点坐标是(1,1),则
b/2a=1 -b²/4a=1
联立解得
a=-1 b=-2
即a=-1
(2)
当顶点坐标是(m,m),m≠0时
b/2a=m -b²/4a=m
b=2am
-4a²m²/4a=m
am=-1
即a与m的关系式是am=-1
y=ax²+bx
=a[x²+bx/a+(b/2a)²]-a×b²/4a²
=a(x+b/2a)²-b²/4a
(1)
顶点坐标是(1,1),则
b/2a=1 -b²/4a=1
联立解得
a=-1 b=-2
即a=-1
(2)
当顶点坐标是(m,m),m≠0时
b/2a=m -b²/4a=m
b=2am
-4a²m²/4a=m
am=-1
即a与m的关系式是am=-1