∵y=x²-4x+3
=x²-4x+4-4+3
=(x-2)²-1
∴抛物线的顶点坐标是(2,-1)
令X=0,得y=3
∴C(0,3)
令y=0,得
x²-4x+3=0
(x-1)(x-3)=0
x-1=0, 或x-3=0
∴x1=1,x2=3
∴抛物线与X轴的交点为A(1,0),B(3,0)
则AB=2
∴S△ABC=½×2×3=3.
∵y=x²-4x+3
=x²-4x+4-4+3
=(x-2)²-1
∴抛物线的顶点坐标是(2,-1)
令X=0,得y=3
∴C(0,3)
令y=0,得
x²-4x+3=0
(x-1)(x-3)=0
x-1=0, 或x-3=0
∴x1=1,x2=3
∴抛物线与X轴的交点为A(1,0),B(3,0)
则AB=2
∴S△ABC=½×2×3=3.